Kill faster :p
Sorry, had to say it.
But you could look into the StickHow (if using KA) and try to have your melee surround the mob to equalize the push.
>> If pets, adjust puller/tank starting poin so he/she is in center of group and pets attack from all sides.
Set Tank with back to a wall/corner/immovable object.
>>Proper locations can be key to safe / successful fights.
Make sure your not using any spells or items that push or knockback the mob.
Use less Meleeers, more Casters.
Kill faster (less fight time less push).
Push has always been an issue (from both PC and mobs) that can be difficult to control.