I am working on this now, but on a different slant. I am taking the royal knights out of the game for now, although I like your idea for a minor nobility type unit, and replacing them with a knight from a chivalric order, like the Knights of the Garter for England. They can only be built by having a royal palace, which I have made unique, limiting them to be buildable in one province only. The Feudal and Chivalric knights are the ones that I am currently using for the minor nobility. It is still in the early stages though. Right now my Polish knights are riiding their horses facing backwards and hanging off of the side.