Weird rushing of summoned archers

I was playing Timber Turncoat, when I noticed that my archers, formerly in a tight formation:

suddenly just split apart like this:

like something had exploded in the midst of them right after they had killed a scout. I noticed similar behavior with the soldiers in Zoo Keeper. The soldier kills a munchkin, then suddenly rushes forward before returning to his post. WHat is going on?

Every unit you can command does this sometimes, I think I even saw enemies do it and definitely my hero sometimes.
So in general, you didn’t do anything wrong. Just try to split your troops a bit more, as clustering seems to make this more likely. Sadly two units engaged in close combat seems to count already as clustering, so archers should be preferred over soldiers. Just my observations.

It’s an unknown, frustrating bug sometimes seen in the game, possibly introduced deep in the depths of the collision handling system. I’ll be happy the day I find it, since it makes things hard to balance.