..or fix monsters AI so they dont break their neat formations and stand on top of each other via line-of-sight exploit/just let you run past them like that makes any kitten sense.
Dont know how fr its implemented but theres an specific part about “group formations” that could kill the “stacks”, lamely i dont remember the minute:
http://www.gdcvault.com/play/1021848/Building-a-Better-Centaur-AI