Remember: This is NOT a family castle managing simulator!
It is a medieval RPG, that focuses on combat, story, historial accuracy and realism.
It’s not realistic for a blacksmith’s son to become landowner in a couple of years, in medieval time. It’s goddamn near impossible!
A deep, realistic family system is also something, that propably won’t be in the game, simply because it’s hard to code. And also because of the technology.