My income is high enough to create these kingdoms in a fairly high speed. My ruler is still in his thirties, so plenty of time left. And the Mongolians have not bothered me yet. And each king is happy to have become one, of course.
As for other unhappy-beyond-repair vassals, it's quite easy to find enough people who are willing to kill them.
There aren't that many pissed off vassals at all, actually.
Yes, I wish I had put some more effort into reforming Suomenusko, but it was too late when I thought about it. On the other hand, England and France would've eaten me alive. I am now the most powerful leader out there, but that wasn't the case when I converted to catholicism.
I've got an elective monarchy, by the way. Quite fascinating, but also a bit dangerous, as it seems you might continue as a vassal of your own empire after the ruler's death.
