I really don't get this. I had a guard with a Patrol package around a town. I placed 1 horse next to the xmarker start. He got on and rode the patrol. I extend the patrol as the town expands and put him to sleep in a guardhouse, when he wakes his patrol start is directly outside with a horse next to it - he doesn't get on. I put another horse on 1 of the patrol "corners" xmarker, he stops (Patrol Data 2) shoves the horse out the way and walks on. Make another NPC similat schedule, patrol is night as opposed to day, same thing walks past the horse. Why?

There is a checkbox in the 'flags' tab of the package for 'Ride Horse', check that and they will always search for a nearby horse to ride. Otherwise it's random and/or they never will.