I have added patrols for a bunch of my missions and I am now in the process of removing them. They only fire-off haphazardly, they don't start moving until the player is within a certain range, they cause mobs to vanish under the floor on a lot of ground maps, etc.
One of the missions I played for the challenge, has patrols in a hallway. Very buggy behavior.... the guys walk down the hallway and disappear occasionally then reappear.... actually... I think they may have been going into the ceiling somehow.
They are utterly inconsistant, I had 3 patroled mobs (set-up the exact same way) all in the same area, doing looped routes in a series of concentric rings. The middle one works about half the time. The inner and outter ones worked for a short time then stopped working.
I believe it was stated that they only work properly once the mission has been published.
Even then some don't start patrolling as they should. I also had to remove a couple patrols because they started too far from the player, and it was pointless to tell the player where the patrol was as it's was intended to be surprise to the player.
Patrols are useful only when they work, which they don't reliably do.