As most warfare in the time period of the mod is phalanx based, the phalanx is going to need to be tweaked to be almost perfect.
There are a number of stats which are important in representing the true nature of hoplite warfare. I am not trying to tell the modders how to sow the stats here, I am merely stating the things I have found from messing around with stats for ages.
Okay so the hoplite phalanx goes as follows:
Try to break the enemy with a charge
Try to maintain discipline
Try to push the enemy
Try to break the enemies' morale.
Casulties were usually light until the rout, as far as i can tell so I think the whole emphasis of hoplite warfare should be on breaking the morale of your enemy.
Now the first way to minimise casulties is to have a low attack value and high defense skill. Not armour, not shield, but defense skill. This judges the individual's ability to withstand melee attacks. Armour and shield are also important, but there stats need to be lower as they relate to missile attack as well. If you make em too high, missiles become useless.
Secondly, is formation. For well drilled troops such as the Spartans they will need a tighter formation. This is not done by giving them a special ability, but simply by giving them the extremely disciplined attirbute, and narrowing the space between men. I dunno if this mod is using shield wall, but if it does then the formation will be real tight.
Thirdly is charge values. I have not messed around much with these, since they were not working in 1.2, however obviously troops that were better at disrupting the enemy lines should have a higher value. Note that mass plays an important part in this, and must be use din conjunction with charge values.
Fourthly is morale. Morale is a tricky one, as I found out when making my morale mod's for RTR 6.0. It needs to be high enough to stop instant rout, but also not allow them to fight to the death. This is simply a case of trial and error, and once you find some good numbers, is best not to stray too far.
Hope all this helps.