Servius, do you need a new family member to lead an army or to govern? Just use captains in fighting those rebels (for promotions). Also, the longer you play, the more family members you will get anyway. In additioin, early in the game, you won't have the "learning centers" so the bonus won't be that big if there are any at all, especially when the generals cost money per turn as well.

Personally, I like the RTW system. The limited characters make them very special. For example,the faction heir I picked to lead my conquering army developed a -3 penalty to order and popularity with the senate so I had him disinherited.

I like RPG aspect of that as opposed to the by-the-numbers MTW characters.