once hired guards come back, they shouldnt come back, but in place, you could kill someones guard, and put your own, play a nice little trick on them if they\'re to cheap to hire a good guard.
And as for city guards they should respawn sometime, but not very often, that way if the city is attacked, people dont/cant rely on the guards to protect them, if they need, weak people can hide in buildings and what not and hope they arent found.