One of the fundamental difference I've noticed between Rome 2 and Attila+Shogun is that Rome allows you to withdraw engaged units with relative ease while Attila/Shogun punishes you with massive casualties.

This is rather detrimental as it makes cavalry into a 1-2 use unit with massive casualties rate for almost every battle.

Im saying is not that cavalry in its current state is UP,but rather the fact that cycle charging or cavalry withdraw of any-kind is unviable,if u withdraw a unit,basically everyone in the front ranks will die in a very short span(3-8 seconds) of time even if its cataphracts,whereas if u leave them in melee,they could last 5+ minutes on their own(but lose regardless).

I might add that units do not even needs to be fully engaged to receive withdraw casualties,even partially engaged units gets smacked heavily by the withdraw bat.
I would figure that it is in the game to balance the massive 'OPNESS' of cavalry in the vanilla game,something that is not present in the mod.
Is this difference something hard coded into the game?Or is it something could be changed by modding in the future?