You could have all of them hooked up with a switch trigger that would give em an alternate set of fleeing waypoints once the trigger was tripped
kinda like how you make a dood go from a set of base perimeter patrol cycle waypoints to a set of seek and destroy waypoints or the like once an alarm goes off..
So your switch trigger has a
countside command in its activation field, and when the proper Side has less than the specified number of guys alive on it they will switch to a new set of waypoints
You could also just have a trigger with the
countside for activation and then have it tell all your dudes to
allowfleeing 1 and they should just run off on their own all disorganized like..
and don't forget to bring a towel ;D