I don't get it? The judge can already ban all these people, why give the ruler the same power? How would it be a pain for the ruler? Many regions have no knights, most have very few, so there's little collateral here. Plus, the collateral seems really unfun for those involved.
It's also completely lopsided. Rogues have no recruitment centers, no access to banks. Against a duke, this sounds like a rebellion, except where the ones who have all of the traditional advantages in one also get the opponent's only advantage: timing and surprise.
The best compromise I could think of would be to force a secession, which would only work on dukes, and which would need restrictions regarding how many nobles and regions are there for balance purposes, imo.
But in all this, we must always consider what kind of havoc a dickish ruler could do. Sometimes malicious people do get that position, their opposition isn't always the "bad guys".
