where on the battlefield would they spawn exactly,either they spawn at the default spawn point, thus making that a target to defend, or keep away from. for it to make sense it would spawn outside the map (and then extend the map to chase camp followers) or just let it be a random event generated outside the players control.Yes and historically it happened that campfollowers got killed in lost battles. Not by the lord(executed) but by the chasing soldiers.
Lettng them spawn retreating would be a good solution
with the strategy you're suggesting it would be better to spawn them in at start of battle and have them withdraw.
i see no reason to waste computing resources generating extra fleeing characters from an arbitrary point on the map.
i see you make no arguments for your good solution, why would it be better to have them on the map, and how would that benefit realism or gameplay