In my opinion the recruitment of elites should be far more restrictive. Not only the recruitment slots should take far too long to fill - My suggestion is 9 turns, that's how long it takes to recruit "Feudal" elites in RR/RC, but there should be also a recruitment restriction after a certain number is reached, which means no further units shall be recruitable before you lose or disband some of your elites in battle.

Currently, I think that Hellenistic factions such as the AS are overpowered precisely because of that, and not just their big size. After a certain stage in the game, no game mechanics prevents the uncontrollable use of uber units by both the player and the AI, and the AS et all, posessing perhaps the best top tier in the game, become an unrealistic nightmare.