[Soyweiser]

But you can change the types of indies in a prov right? At least that is what the RanDom progam does. So you could then have a new type of barbarian who spawns barbs (Lets call him the barbarian king). And add that to the province.

So, the defense of the province is the barbarian king, and you can only recruit barbarian chiefs there.

You still have to problem that you can enslave the barb king, but that can perhaps be solved by giving it a battleshape into a barbarian chief (with no way of turning back). This could also be used to improve the AI.