Ground Based Locust Swarm

Well, I altered the Locust Swarm ability to create ground units instead of the floating locusts, but now whenever the caster is near a cliff or ramp and such, the units sometimes go out of their way to run up/through it. Does anyone know if there is a remedy for this? Here's an example of what I mean.

Just as a guess, the units in the spell are probably being ordered to attack-move around to locations within the radius of the spell, and it probably doesn't check for easy pathing, since the spell isn't originally designed to work that way.

I don't know of any good recommendations to give to counter this, though. Sorry.