Don't delude yourselves guys, this isn't an intentional feature of the game, it is simply broken. It needs to be addressed by Taleworlds ASAP. It is currently locking every single singleplayer campaign out of well over half of the character progression, and kind of makes it pointless to start a new campaign with the hopes of building a unique character when after a full campaign you haven't even been able to get your basic combat and leadership skills up past the halfway mark.