Modding Rome 2 is harder than modding Medieval 2 and even after reading few guides I'm a little bit confused about where to look or what's to do, so I apologize if this is the wrong place or the questione is already solved somewhere.

I need to change units and mercs recruitment. It's annoying to see barbaric factions with 4 ballistae after few years from the start o lots of amazons, when I need so much time to get good units.
Thank you guys!