I don't think I agree with that first statement, especially if the result is logical and tempered. Yes, such a system would impose (some, likely light) penalties to duchies that would abuse the system, and these penalties did not exist before. I don't think that's necessarily a bad thing. Also, to keep regions from switching often just for better recruitment results, a penalty could be imposed where the region would run at decreased efficiency for a length of time and wouldn't be able to switch again for at least another length days, if not longer (like the estate system did when you switched from production to authority, etc...)
I tend to consider that the game already has a ton of penalties for a ton of stuff, though thank god a bit less since the new estate system. I therefore won't be in favor of anything that increases the average necessity to do maintenance, unless it's easily avoidable (such as by not putting your capital on your border when you have a perfectly central candidate city).
