Ducal independence? Isn't that, you know, a secession?
No, it would mean that duchies would still wave the flag of a certain realm, but could engage in interducal wars and diplomacy. I.e. the centralized power is heavily reduced and will be replaced by several dukes with more power, that
can (but therefore not should) fight amongst one another over regions or whatnot. It would inject a massive amount of fun into huge empires, I believe. I mean, imagine you would actually be fighting for your /duke/ instead of for your realm. Much more accurate, too. Medieval nobility didn't fight for their kingdom. They fought for their liege. That bond is not enough stressed in Battlemaster.
