SP - Player, NPCs & Troops Lock for garrison troops

[Emax]

After loading up my city with elite troops in the garrison, I split off my companions to wage some war and the first thing they did was head to the city to grab all those elite garrison troops, with a simpsons-style "yoink:.

So please, lets have a "lock" option for garrisons so that no one besides the player can withdraw troops from it.