If you have enough people its sometimes good to put one man in charge of the monsters, and leave the GM to be impartial.
We frequently did that in D&D and some other proper RPG's as well.
It was simply a game where unbalanced shit happened.
The party tank got the grapple skill and some other weird skill that I forget. Basically no monster could get past him and basically he was the perfect tank and any monsters from the front could not do anything at all because their attacks would be ignored by the dual shield wielding tank.
However, at the same time the Gm got some lucky as all hell hits on our squishies which took us down to an insanely low life pool. When we got to the end, we realized the boss who could not regenerate could be killed by the spirit wolf slowly which does 2 damage a turn ignoring armor, while we stayed back and watched.
So much rage on both sides.