[Sombre]

If you make disbanding cause unrest all that will happen is people will either not use it or feel forced to move all their guys to one sink province in order to disband them. Is that realistic? Is that fun? Does it satisfy the people who are asking for the disband command in the first place? No on all counts.

Dom3 isn't even a realistic game. It's far more arcadey that a lot of 'risk' inspired strategy games. I mean this is a game with simple recruitment, economic, political, religious, diplomatic etc systems. If you want extra annoyances based on 'realism' then feel free to roleplay that your commander got drunk that day and failed to lead his army to attack or that your troops are unable to march during winter due to a lack of adequate blankets, or that they'll all go back to tending the crops during the summer. Why should everyone else be forced to deal with extra pointless micromanagement?