Question about cultures

I have a question about the cultures in vanilla RTW. It seems that there are only 6 (roman, barbarian, carthaginian, greek, eastern and egypt).
Is it possible to add more?
If not, is it possible to change, say, German to have eastern (or another) culture instead of barbarian? Is it possible to break one faction off their original culture and put them in another?

This is mostly just for editing sound files.

Thanks for the help.

No, not really, and no. The "not really" is because you can always just rename, say, the Parthians to "Germans" and give them German units instead of Parthian ones, basically replacing the Parthians with the Germans.

-Simetrical