Which will likely lead to "bait estates", where a realm in need of Nobles sets up the nicest estate then shrinks it once it's filled.
Which will lead to angry players that don't like that lord, and won't stay. If you do something like that, you're shooting yourself in the foot. If I was a lord in that realm, and knew that someone was doing that, I would go out of my way to get that knight a better estate somewhere else.