Alot better with 4, as the other 2 ppl can focus on bosses and challenges.
They actually gained 15k before the Leashers.
We hit 50k achievement with 18 enemies still left.
Got people to quit, invited more, kill 1 enemy, and they get achievement also ^_^
Please msg if working on:Halo3, HaloWars, Bioshock2, BorderlandsMadmoxiDLC