A heretic's take on Second Mantinea

[Justin Swanton]

Let's take your reconstruction

This isn't my reconstruction.  I wouldn't actually agree with it.  Nor is it one of Duncan's, so whose is it?

I misunderstood you, apologies.

[Justin Swanton]

For the course of the battle IMHO one can create a coherent picture from all the sources (which is nice). The frontage of units works on the assumption that one infantry file had a width of about a meter whilst a cavalry file has a width of about 2 meters. The width to depth ratio in the diagrams is not to scale. Let me split this over several posts.

Original position.




The Theban and Thessalian cavalry demonstrate in front of the allied line, creating a cloud of dust that obscures Epaminondas' infantry. The entire phalanx (with the exception of the Arcadians and nine subunits of Thebans next to them) wheels by square-shaped subunits - "successive companies" - into column (Xenophon). Presuming the phalanx was 16 deep to begin with, that means that each subunit measured 16x16 men, i.e. a syntagma. The subunits still in line - the 9 Theban units and those of the Arcadians - advance about 16 yards or so. The column of the remaining units advances until the second nine Theban units are largely behind the first nine. These second nine then wheel into line behind the first nine. The units now in line (18 Theban and the Arcadians) advance about another 16 yards. The column advances again until the last 9 Theban units are largely behind the others in line. These last 9 units wheel into line behind the 18 Theban units already in line. The Theban column is now formed, about 48 ranks deep and 144 files wide - a theoretical 6912 men.

The Tegeans wheel into line and take up position alongside the Theban column. The Euboeans continue to advance in column until they are past the Arcadians. They wheel into line, taking up position on the left flank. They (or some of them plus mercenaries, leaving the rest in the main phalanx) will be used to secure the heights on the Theban left.

The rest of the column, led by the Locrians, advances until it is next to the Tegeans. The column then wheels into line alongside the Tegean-Theban-Arcadian battleline.

As the Theban column advances, the units on either side of it echelon back, creating a wedge that advances " prow on, like a trireme". Epaminondas, at the right front corner of the column (the normal place for a unit commander) plans to "strike and cut through" the enemy phalanx at the spot covered by the Spartans, and push the rest of the phalanx to rout in consequence.

Notice how the Theban right has been completely denuded of hoplites save those on the hills. Epaminondas had anticipated this, relying on the screen of cavalry and hoplites "to prevent the Athenians on the left wing from coming to the aid of those who were posted next to them", "desiring to create in them the fear that if they proceeded to give aid, these troops would fall upon them from behind". The outflanking would be done by the cavalry whilst the infantry hoplites pin the Athenians in place.

[PMBardunias]

Funnily enough, after our rehearsal game we have gone for putting the Tegeans and other Arkadians on the extreme left opposite the Mantineians, with the deep Theban formation opposite the Spartans

I'll bet Epameinondas would have loved a redo as well .  I think the way the battle plays out makes sense if the Thebans hit the force from Mantinea on the right. Xenophon tells us that: 23] "Meanwhile Epaminondas led forward his army prow on, like a trireme, believing that if he could strike and cut through anywhere, he would destroy the entire army of his adversaries." Why not say "take out the Spartans" if that is what the intent was? The numerous quotes describing Theban advancement beyond the battle line and the Spartans hitting the section of the Theban force where Epameinondas was stationed makes sense if the Theban deep formation moved through the Mantinean line and past the Spartan section of the line on their right.

[Justin Swanton]

Funnily enough, after our rehearsal game we have gone for putting the Tegeans and other Arkadians on the extreme left opposite the Mantineians, with the deep Theban formation opposite the Spartans

I'll bet Epameinondas would have loved a redo as well .  I think the way the battle plays out makes sense if the Thebans hit the force from Mantinea on the right. Xenophon tells us that: 23] "Meanwhile Epaminondas led forward his army prow on, like a trireme, believing that if he could strike and cut through anywhere, he would destroy the entire army of his adversaries." Why not say "take out the Spartans" if that is what the intent was? The numerous quotes describing Theban advancement beyond the battle line and the Spartans hitting the section of the Theban force where Epameinondas was stationed makes sense if the Theban deep formation moved through the Mantinean line and past the Spartan section of the line on their right.

Didorus does affirm that the Theban column engaged the Spartans: "he led his battalion in the charge and was the first to hurl his javelin, and hit the commander of the Lacedaemonians." "The Lacedaemonians, overawed by the prestige of Epameinondas and by the sheer weight of the contingent he led, withdrew from the battle".

Also Nepos: "He was recognised by the Lacedaemonians, and since they believed that the death of that one man would ensure the safety of their country, they all directed their attack at him alone"

Justin implies it as well: "the Spartan youth, incited by the heroism and glorious deeds of the old men, could not be prevented from promptly engaging in the field."

Plutarch affirms the Thebans engaged the Spartans: "A few days afterwards a battle was fought near Mantinea, in which Epaminondas had already routed the van of the Lacedaemonians, and was still eagerly pressing on in pursuit of them, when Anticrates, a Spartan, faced him and smote him with a spear" "In the battle of Mantineia he (Agesilaos) urged the Spartans to pay no attention to any of the others, but to fight against Epameinondas"

The Theban column would not be as wide as the Spartan deployment, and if Epaminondas struck the right half of the Spartan line and pushed ahead of his Tegean support, that would leave the Spartans on his right free to target him.

Xenophon doesn't specifically mention Epaminondas taking out the Spartans but just piercing the line somewhere possibly because he had sympathy for Sparta and didn't want to emphasis too much the fact that it was the Spartans who were defeated by Epaminondas. He had served under Spartan commanders and had a friendship with Agesilaus.

[Justin Swanton]

Let me wrap up my reconstruction of the course of the battle. I think it possible to reconcile pretty much all the source material with a couple of exceptions which aren't really important.

Having completed his formation of the Theban column, Epaminondas recalls the Theban and Thessalian cavalry to the left wing in front of the Arcadians. The cavalry form a line 16 ranks deep matching the width of the Athenian cavalry deployment, and the horses are interspersed with hamippoi and peltasts (Xenophon) and slingers (Diodorus). It was a "strong column" according to Xenophon. Why "strong"? Xenophon was an experienced military man and he would have known that depth in itself added nothing to the effectiveness of cavalry. But it was the interjection of the missile troops that made the difference: the more depth, the more missile troops could be inserted, the more potent the cavalry unit's missile capability became.

FYI I envisage a mixed cavalry-infantry formation thus:




The Thessalian, Locrian and Eubian cavalry charge the Spartan and Mantinean horse on the other flank. There's no description of the cavalry battle there but Diodorus affirms that "both sides divided the cavalry and placed contingents on each wing." One can assume that the Spartans and Mantineans were routed off the field as there is no mention of them later in the battle when the Eleians came to the rescue.

[Justin Swanton]

Having routed the Spartan and Mantinean cavalry, the Eubian, Locrian the Thessalian horse move to the right of the Hoplites deployed in the hills. I suspect the hoplite line was thin - perhaps as little as 4 deep (hence about 2000 hoplites) - as the plan was for the cavalry to move around to the rear of the Athenians if they advanced against the hoplites. Hit from both sides, the Athenians would be disordered and fixed in place, unable to continue any further. A similar idea was supposed to happen on the other flank, with the Theban and Thessalian cavalry outflanking the Mantinean hoplites once the Athenian cavalry was dispatched, and hitting the Mantineans from front and back. In both cases the idea came unstuck.

The Euboeans occupy the heights, ready to support the outflanking of the Mantineans, whilst the Theban and Thessalian horse engage the Athenian cavalry with a blitz of missiles.

The Theban column continues to advance and the entire line is now echeloned. The allied line also advances with the Spartans to contest the higher ground in the centre right.

[Justin Swanton]

The Athenian cavalry are outfought and retire in good order back through the Mantineans and Arcadians. To do this the hoplites had to be in open order, with 4-foot wide gaps between each file through which the horses could pass....like a knife through butter (couldn't resist!). Once the Athenians are through, the files double to intermediate order, presenting a solid front against the enemy.

Shouldn't wargaming rules cater for this?

The Theban column smashes into the right half of the Spartan line.

[Justin Swanton]

The allied line on the left continues to advance and the Athenian hoplites draw near to the thin hoplite line deployed in the hills. The Thessalian and other cavalry form column and begin to head for the rear of the Athenians. This is something Thessalians would have been particularly good at as they habitually used the rhombus formation, enabling them to change direction in 90 degree increments at a moment's notice, making them highly manoeuvrable.

Meanwhile on the other flank the Theban column drives the Spartans back. The Thessalian and Theban cavalry and LI hammer the Mantineans with a shower of missiles.

[Justin Swanton]

The Thessalian, eubian and Locrian cavalry move to the rear of the Athenian foot, now engaged with the hoplites, and begin to disorder them, forcing their rear ranks to turn and face the threat hence weaking their efforts to the front. The Athenians are soon in trouble: "the Athenians were exhausted and had turned to flee" (Xenophon).

On the other wing the Theban column contined trundling forwards whilst the Theban and Thessalian cavalry began to outflank the Mantineans "Now the Theban horse did not follow up the fugitives, but, assailing the phalanx opposing them, strove zealously to outflank the infantry." But the Athenian horse had reordered themselves and moved towards the right flank, turning to face the Thessalians (I suspect they led the outflanking column) and Euboeans on the heights. The allies were beginning to pull the first of several rabbits out of the hat.

The light troops interspersed with the Thessalian and Theban horse fall back out of the cavalry units and move in column towards the other flank. This was probably planned from the start by Epaminondas, as he knew his right would need all the help it could get.

[Justin Swanton]

The cavalry busy outflanking the Mantinean foot are forced to fall back before the Athenian horse, who attack the Euboeans on the heights. I don't know how Greek cavaly could defeat hoplites in a frontal fight, especially on uneven ground, but they managed it. Rabbit number two.

On the left wing, the Eleian cavalry finally decide which side needs them most and move across to face the enemy cavalry harassing the Athenians. Rabbit number three.

[Justin Swanton]

The Thessalian, Locrian and Eubian cavalry on the left pull back smartly from the Eleian cavalry (or are routed by them). This leaves the Athenian hoplites free to engage the thin line of enemy hoplites in front of them, now reinforced by the light troops from the other flank. Even reinforced, the hoplites cannot withstand the Athenians who cut through them, killing many: "Furthermore, while the intermingled footmen and the peltasts, who had shared in the victory of the cavalry, did make their way like victors to the region of the enemy's left wing, most of them were there slain by the Athenians." (Xenophon)

On the right the Athenian cavalry destroy the Euboeans and seize the heights - possibly the Euboeans had formed column to move around to the rear of the Mantineans and were caught like that by the Athenians. The Theban and Thessalian cavalry has - presumably - pulled back by this time through the Arcadians who engage the Mantineans. Or possibly the Thebans and Thessalians continue to pepper the Mantineans.

Meanwhile the Theban column continues to plough forward. It separates from the Tegeans who themselves cannot make any progress against the Spartans (naturally). At this point Epaminondas is through the Spartan line and in the open. He is recognised by nearby Spartans who target him with their spears and kill him. It appears that hoplites had reverted to the homeric practice of using throwing spears.

At this point - after a tussle over Epaminondas' body - both sides decide to call it a day.

[PMBardunias]

Didorus does affirm that the Theban column engaged the Spartans: "he led his battalion in the charge and was the first to hurl his javelin, and hit the commander of the Lacedaemonians." "The Lacedaemonians, overawed by the prestige of Epameinondas and by the sheer weight of the contingent he led, withdrew from the battle".

I am with Polybius on Ephorus. That any Theban hoplite threw his "javelin" at the commander of the Lakedaimonians renders this account something to be taken with a grain of salt in my opinion.

"[2] For the most capable foot-soldiers of that time, Boeotians and Lacedaemonians, whose lines were drawn up facing one another, began the contest, exposing their lives to every risk. After the first exchange of spears in which most were shattered by the very density of the missiles, they engaged with swords. And although their bodies were all locked with one another and they were inflicting all manner of wounds, yet they did not leave off; and for a long time as they persisted in their terrible work, because of the superlative courage displayed on each side, the battle hung poised. [3] For each man, disregarding the risk of personal hurt, but desirous rather of performing some brilliant deed, would nobly accept death as the price of glory. [4] As the battle raged severely for a long time and the conflict took no turn in favour of either side, Epameinondas, conceiving that victory called for the display of his own valour also, decided to be himself the instrument to decide the issue. So he immediately took his best men, grouped them in close formation and charged into the midst of the enemy; he led his battalion in the charge and was the first to hurl his javelin, and hit the commander of the Lacedaemonians. Then, as the rest of his men also came immediately into close quarters with the foe, he slew some, threw others into a panic, and broke through the enemy phalanx. [5] The Lacedaemonians, overawed by the prestige of Epameinondas and by the sheer weight of the contingent he led, withdrew from the battle, but the Boeotians kept pressing the attack and continually slaying any men who were in the rear rank, so that a multitude of corpses was piled up."

The foregoing makes little sense as a standard hoplite battle, but it mirrors in some ways Coronea, with the "second phase coming on the heels of a routed Mantinea.

Also Nepos: "He was recognised by the Lacedaemonians, and since they believed that the death of that one man would ensure the safety of their country, they all directed their attack at him alone"

Yes, as they routed the Mantineans and tried to pass on their unshielded side.

Justin implies it as well: "the Spartan youth, incited by the heroism and glorious deeds of the old men, could not be prevented from promptly engaging in the field."

Sure, but this does not mention who or how they engaged. Additionally, what does it mean for Spartans who walked into battle to engage promptly?

Plutarch affirms the Thebans engaged the Spartans: "A few days afterwards a battle was fought near Mantinea, in which Epaminondas had already routed the van of the Lacedaemonians, and was still eagerly pressing on in pursuit of them, when Anticrates, a Spartan, faced him and smote him with a spear"

We would first have to define what the VAN of 12 ranks of hoplites is.

"In the battle of Mantineia he (Agesilaos) urged the Spartans to pay no attention to any of the others, but to fight against Epameinondas"
 

Yes, again as they pass, when Agesilaus is more likely to be in Proximity to Epameinondas.

The Theban column would not be as wide as the Spartan deployment, and if Epaminondas struck the right half of the Spartan line and pushed ahead of his Tegean support, that would leave the Spartans on his right free to target him.

Sure, this is possible, but because I think it unlikely that the Tegeans were on the left for a variety of reasons, I see no reason to invoke this explanation.

Xenophon doesn't specifically mention Epaminondas taking out the Spartans but just piercing the line somewhere possibly because he had sympathy for Sparta and didn't want to emphasis too much the fact that it was the Spartans who were defeated by Epaminondas. He had served under Spartan commanders and had a friendship with Agesilaus.

Meh, the ol' Xenophon was covering for his friends does not work for me so much. He describes many routs of Spartiates and the idiocy of his friend Agesilaus.

[Justin Swanton]

Didorus does affirm that the Theban column engaged the Spartans: "he led his battalion in the charge and was the first to hurl his javelin, and hit the commander of the Lacedaemonians." "The Lacedaemonians, overawed by the prestige of Epameinondas and by the sheer weight of the contingent he led, withdrew from the battle".

I am with Polybius on Ephorus. That any Theban hoplite threw his "javelin" at the commander of the Lakedaimonians renders this account something to be taken with a grain of salt in my opinion.

"[2] For the most capable foot-soldiers of that time, Boeotians and Lacedaemonians, whose lines were drawn up facing one another, began the contest, exposing their lives to every risk. After the first exchange of spears in which most were shattered by the very density of the missiles, they engaged with swords. And although their bodies were all locked with one another and they were inflicting all manner of wounds, yet they did not leave off; and for a long time as they persisted in their terrible work, because of the superlative courage displayed on each side, the battle hung poised. [3] For each man, disregarding the risk of personal hurt, but desirous rather of performing some brilliant deed, would nobly accept death as the price of glory. [4] As the battle raged severely for a long time and the conflict took no turn in favour of either side, Epameinondas, conceiving that victory called for the display of his own valour also, decided to be himself the instrument to decide the issue. So he immediately took his best men, grouped them in close formation and charged into the midst of the enemy; he led his battalion in the charge and was the first to hurl his javelin, and hit the commander of the Lacedaemonians. Then, as the rest of his men also came immediately into close quarters with the foe, he slew some, threw others into a panic, and broke through the enemy phalanx. [5] The Lacedaemonians, overawed by the prestige of Epameinondas and by the sheer weight of the contingent he led, withdrew from the battle, but the Boeotians kept pressing the attack and continually slaying any men who were in the rear rank, so that a multitude of corpses was piled up."

The foregoing makes little sense as a standard hoplite battle, but it mirrors in some ways Coronea, with the "second phase coming on the heels of a routed Mantinea.

This is one of the passages I take with a grain of salt. The Theban column formed up according to Epaminondas' plan and with him at its head, so the idea that he formed it ad hoc after the battle had been raging for some time does smack of dramatic licence. However several sources affirm that the hoplites used throwing spears and the fact that several took credit for killing Epaminondas confirms this. If they had all been fighting hand-to-hand then only the Spartan in front of Epaminondas could have killed him and everyone would know who that was.

Also Nepos: "He was recognised by the Lacedaemonians, and since they believed that the death of that one man would ensure the safety of their country, they all directed their attack at him alone"

Yes, as they routed the Mantineans and tried to pass on their unshielded side.

Or as one half of the Spartans were routed leaving Epaminondas exposed to the other half.

Justin implies it as well: "the Spartan youth, incited by the heroism and glorious deeds of the old men, could not be prevented from promptly engaging in the field."

Sure, but this does not mention who or how they engaged. Additionally, what does it mean for Spartans who walked into battle to engage promptly?

True. I took it as the Spartans being the first to engage the Theban line - other units engaging later as they advanced against the inclined hoplites. But it is rather vague.

Plutarch affirms the Thebans engaged the Spartans: "A few days afterwards a battle was fought near Mantinea, in which Epaminondas had already routed the van of the Lacedaemonians, and was still eagerly pressing on in pursuit of them, when Anticrates, a Spartan, faced him and smote him with a spear"

We would first have to define what the VAN of 12 ranks of hoplites is.

What is clear is that Epaminondas with the Theban column is driving the Spartans back, not the Mantineans.

"In the battle of Mantineia he (Agesilaos) urged the Spartans to pay no attention to any of the others, but to fight against Epameinondas"

Yes, again as they pass, when Agesilaus is more likely to be in Proximity to Epameinondas.

Not quite. Agesilaus would have told his men before the battle started to take on Epaminondas (no possibility of giving that kind of instruction in mid-battle). Thus he knew the Theban column was headed for the Spartan part of the line. Agesilaus himself would not have taken part in the fighting being an old man in his 80s.

The Theban column would not be as wide as the Spartan deployment, and if Epaminondas struck the right half of the Spartan line and pushed ahead of his Tegean support, that would leave the Spartans on his right free to target him.

Sure, this is possible, but because I think it unlikely that the Tegeans were on the left for a variety of reasons, I see no reason to invoke this explanation.

Do tell about the variety of reasons. 

Xenophon doesn't specifically mention Epaminondas taking out the Spartans but just piercing the line somewhere possibly because he had sympathy for Sparta and didn't want to emphasis too much the fact that it was the Spartans who were defeated by Epaminondas. He had served under Spartan commanders and had a friendship with Agesilaus.

Meh, the ol' Xenophon was covering for his friends does not work for me so much. He describes many routs of Spartiates and the idiocy of his friend Agesilaus.

Can you give examples? It would be interesting to see the context. This battle is different in that Sparta's military reputation was definitively eclipsed as was that of Agesilaus.

Oh, and one other problem with having the Thebans engage the Mantineans rather than the Spartans. The Thessalian and Theban cavalry drove the Athenian horse back through their own infantry: "even in their retreat they did not break their own phalanx". The Thessalians and Thebans then engage that phalanx: "Now the Theban horse did not follow up the fugitives, but, assailing the phalanx opposing them, strove zealously to outflank the infantry."  Which phalanx was that? If the Theban column was engaged with the Mantineans at the extreme right of the allied line, then the Thessalians and Thebans would have nobody to engage, nor would the Athenian cavalry have anyone to pass through.

[PMBardunias]

However several sources affirm that the hoplites used throwing spears and the fact that several took credit for killing Epaminondas confirms this. If they had all been fighting hand-to-hand then only the Spartan in front of Epaminondas could have killed him and everyone would know who that was.

If you really believe that early 4th century hoplites regularly threw spears, outside of the telling exceptions like on the slope at Munychia, then I doubt we will come to agreement on much.

 

Not quite. Agesilaus would have told his men before the battle started to take on Epaminondas (no possibility of giving that kind of instruction in mid-battle). Thus he knew the Theban column was headed for the Spartan part of the line. Agesilaus himself would not have taken part in the fighting being an old man in his 80s.

I don't know, he went off to Egypt after this. He was surely more spry than I am and I just marched all over Plataia in full panoply.  If a man can call for "one more step" and be heard by those around him, another can yell "kill that particular dude!" to the guys in front of said dude.

Do tell about the variety of reasons. 

In short, from my experience you would need to form such a deep phalanx on the end of the line of the parataxeis. It would be exceedingly difficult to drag adjacent taxeis along in the wedge you drew above. They always fracture along unit lines. This is why we can see taxeis right beside eachother moving in different speeds (Spartans and anyone beside them) or different directions (most battles somewhere in the middle of the battleline as they win on the right and lose on the left). The Thebans won, yet lost this battle because of the inability for their flanking units to keep up with them. I believe the whole reason Epameionondas attacked as he did was to use the terrain to protect his left flank. That would be much better protection than Tegeans.

 

Can you give examples? It would be interesting to see the context. This battle is different in that Sparta's military reputation was definitively eclipsed as was that of Agesilaus.

Oh, and one other problem with having the Thebans engage the Mantineans rather than the Spartans. The Thessalian and Theban cavalry drove the Athenian horse back through their own infantry: "even in their retreat they did not break their own phalanx". The Thessalians and Thebans then engage that phalanx: "Now the Theban horse did not follow up the fugitives, but, assailing the phalanx opposing them, strove zealously to outflank the infantry."  Which phalanx was that? If the Theban column was engaged with the Mantineans at the extreme right of the allied line, then the Thessalians and Thebans would have nobody to engage, nor would the Athenian cavalry have anyone to pass through.

You are really going to make me quote such common descriptions by Xenophon as "yea the Spartiates got their asses handed to them, but they had been drinking after all" at Leuktra and "Agiselaus surely did not take the wisest course" when he met the Thebans head on at second phase Coronea.

As for the cavalry. The contingents on the Mantinean side broke and ran behind their own phalanx, which was engaged with the Thebans.

Diod 85.8 "on the other flank both cavalry forces lashed at one another and the battle hung for a short time in the balance, but then, because of the number and valour of the Boeotian and Thessalian horsemen, the contingents on the Mantineian side were forced back, and with considerable loss took refuge with their own phalanx"

[Justin Swanton]

If you really believe that early 4th century hoplites regularly threw spears, outside of the telling exceptions like on the slope at Munychia, then I doubt we will come to agreement on much.

We have two sources that affirm Epaminondas was killed by a thrown spear:

As missiles flew thick and fast about him, he dodged some, others he fended off, still others he pulled from his body and used to ward off his attackers.

they saw Epaminondas himself fall valiantly fighting, struck down by a lance (sparo) hurled from afar.

I'm not saying that early 4th century hoplites regularly threw spears, but the sources seem to indicate that at least some Spartan hoplites did in this battle. It's at least possible the Spartans tried rear rank missile support as a refinement - the late Romans ended up doing the same thing. I like to reconcile the sources if possible.

Not quite. Agesilaus would have told his men before the battle started to take on Epaminondas (no possibility of giving that kind of instruction in mid-battle). Thus he knew the Theban column was headed for the Spartan part of the line. Agesilaus himself would not have taken part in the fighting being an old man in his 80s.

I don't know, he went off to Egypt after this. He was surely more spry than I am and I just marched all over Plataia in full panoply.  If a man can call for "one more step" and be heard by those around him, another can yell "kill that particular dude!" to the guys in front of said dude.

Oh sure, he was fit and healthy for his age, but I just can't see an octogenarian holding an aspis in the front rank of a phalanx and taking part in an othismos shoving match whilst stabbing at the chap in front of him. Call it a failure of imagination.

In short, from my experience you would need to form such a deep phalanx on the end of the line of the parataxeis. It would be exceedingly difficult to drag adjacent taxeis along in the wedge you drew above. They always fracture along unit lines. This is why we can see taxeis right beside eachother moving in different speeds (Spartans and anyone beside them) or different directions (most battles somewhere in the middle of the battleline as they win on the right and lose on the left). The Thebans won, yet lost this battle because of the inability for their flanking units to keep up with them. I believe the whole reason Epameionondas attacked as he did was to use the terrain to protect his left flank. That would be much better protection than Tegeans.

I see the Arcadians on the Theban left rather than the Tegeans (who would have held station on the Theban right). The Arcadians were fronted by a deep cavalry formation reinforced with peltasts and slingers. That was a sufficient flank guard for the Theban column.

As regards the wedge, I do see the line fracturing along unit lines, i.e. the inclined line would be stepped rather than a smooth front. Inclined lines were definitely a thing as the tacticians make clear. It's simple enough to tell the unit commanders: "keep pace with the back rank of the unit to your left." Simpler in fact than telling them: "wheel to your left and take up station behind the unit now in front of you to form a column." Which they were capable of doing.

Can you give examples? It would be interesting to see the context. This battle is different in that Sparta's military reputation was definitively eclipsed as was that of Agesilaus.

Oh, and one other problem with having the Thebans engage the Mantineans rather than the Spartans. The Thessalian and Theban cavalry drove the Athenian horse back through their own infantry: "even in their retreat they did not break their own phalanx". The Thessalians and Thebans then engage that phalanx: "Now the Theban horse did not follow up the fugitives, but, assailing the phalanx opposing them, strove zealously to outflank the infantry."  Which phalanx was that? If the Theban column was engaged with the Mantineans at the extreme right of the allied line, then the Thessalians and Thebans would have nobody to engage, nor would the Athenian cavalry have anyone to pass through.

You are really going to make me quote such common descriptions by Xenophon as "yea the Spartiates got their asses handed to them, but they had been drinking after all" at Leuktra and "Agiselaus surely did not take the wisest course" when he met the Thebans head on at second phase Coronea.

The sources affirm that the Theban column attacked and drove back the Spartans, so why Xenophon doesn't make that clear is up for discussion. I hypothesise that on this occasion he didn't want to rub it in as it was such a definitive humiliation for Sparta. He had some reason.

As for the cavalry. The contingents on the Mantinean side broke and ran behind their own phalanx, which was engaged with the Thebans.

Diod 85.8 "on the other flank both cavalry forces lashed at one another and the battle hung for a short time in the balance, but then, because of the number and valour of the Boeotian and Thessalian horsemen, the contingents on the Mantineian side were forced back, and with considerable loss took refuge with their own phalanx"

Sure. The Theban column had engaged the Spartans whilst the Theban and Thessalian cavalry attacked the Athenian cavalry deployed in front of the Mantinean hoplites. The Athenians pulled back through the hoplites to escape the missile barrage they were getting from the light infantry interspersed within the Theban/Thessalian horse. The upshot is that the Theban column did not engage the extreme right of the enemy line as that would make no sense of the Athenian cavalry taking refuge with their own phalanx.