I was thinking about the problem with FO3 caravans getting themselves killed and disappearing. Crow and his buddies etc. Often this is solved by setting them as essential.
A better solution in my opinion would be additional "smalltalk" topics that you get as greeting or overhear. Things like: "I haven't seen X's caravan in a while" or "Have you seen? Someone else seems to be running the armour caravan now instead of Crow" or whatever, triggered when the person in question gets themselves killed.
Provided you got some kind of clue that a merchant was dead, and they were replaced by a generic if they died, it would be a lot more realistic. Plus the bad characters out there could make a living raiding caravans without running out of prey/coming up against unkillable targets.