I did figure out one thing about the spawned mobs not following a route. On the first invocation, the mob spawns, and follows the route into the NPC's that will kill him. Then he respawns, and does not follow the route.
The problem is that if the mob is killed before the route is finished, he won't run the route when the mob respawns. If I make the route end just in aggro range, then the mob runs the route, gets aggro, gets killed, respawns, and then runs the route again. If he gets killed before the route is finished, the mob won't run the route again when respawned.
The fragility of the Ring makes me respect even more those who have made good scenarios work
