You can't have historical accuracy in a Warband module at all. Ok, fine. This is only Manassas, so it is not that imbalanced. Raise some stats of (historically) battle hardened troops to represent their experience level at start of the battle/war. But then, how would you represent this in the ongoing war? CSA troops under Lees command OP because of their experience? Yankees UP then? But then pls don't make equal numbers in LBs, because this is not historical accurate. US troops outnumbered CS troops in nearly every battle. And their equipment was better towards the end of the war (repeating rifles, Minié balls, Gatling guns, cast iron artillery). Do you want this for this mod or succeeding mods?
I don't think so.