Originally Posted by
Sar1n
Custom battle rosters are a bit mess right now, but I haven't noticed any missing important Roman units.
You're probably missing the fact that they're available by era. If you select early era for custom battle, you get Camillian troops, middle for Polybian and late for Marian era units. But you can't mix them up in one battle.
Edit: in any case, fixing the custom battle rosters is easy, but tedious. Open the EDU file in Notepad++, last lines of every unit entry is availability for custom battle...it's quite self-explanatory.