That's a really clever idea, I like that a lot as it prevents it spawning when there's online like 15 people online
Elaboration on Genecide65's idea: The caravan is on it's way to a random faction's base. If it reaches their territory, that faction gains some of the rewards you would get for sacking it. other factions can target and loot the caravan, but the faction it was heading to is notified that X faction plundered the caravan meant for them. Could be a way to allow faction politics and stuff to be more involved.