[Psitticine]

"Auto-patrolling" starts with a Defence of 10. It isn't very good compared to a real army patrolling around, especially when that army is made out of speedy and/or numerous troops.

I've caught a few scouts with the auto-patrol, but not many. Still, it ain't bad for free.

Oh, and (just as PvK points out) patrolling of any kind doesn't kill anybody as long as there is no unrest, and then only up to the unrest number.