Or reserve it for a next installment of Crusader kings, but I think it would add something new if they could add the character development of Crusader Kings. Let's say you pick one of the famous families of Rome, Claudii, Jullii, Brutii, (many many more but I'm a noob when it comes to history), or someone from the plebs. Then you try to work your way up, use money to bribe other people to get higher positions, go for the priesthood and become Flamens, Augures or eventually Pontifex Maximus, or go into the political route (pretty much the same as the priest) and become Praetor and eventually Consul, where you have to consolidate your power, make alliances, and go out and raise armies to conquer stuff in the provinces you own. You could marry off your daughter to make alliances, or marry your son to other family's daughers.

Maybe this isn't fitting for this game, but it would make the characters more involving