TL;DR, I had two questions:
A. At least 4 barons for every county, at least 4 counties for every duchy, that means a lot of barons. I know zip about feudalism (that's why I rely on games such as ACKS, so that I don't have to try to read the domesday book and stuff like that), but I've never heard of so many barons. I have three duchies, does that really mean around 400 barons?
B. Where do the extra people go that don't fit into the 4-6 counties in a duchy etc?
I suspect both of these questions have the same fundamental misunderstanding at their core, and that I better hold off on the Big Barony Creation Project until I get some sort of clarification.