Bishoprics just seems like an exploit to me, and anyways I always find it strange that I cannot choose who to give inheritance to.
I'll try and roll Barcelona next. Any other ones out there? Central Europe?
Sending the younger sons to the church, the method used to get rid of extra spawn, seems like an exploit, but offing your offspring is okay?
As I said, both Scotland and Godwin England is Primogeniture. Also Milan, France and Portucale.