Whenever it decides to use browncoats it's like a major "haha, screw you". I was playing that bunker raid or whatever skirmish and was trying to do it with only coalition units. I got into the bunker and had this huge area with two guys facing the hole you come down, one has the browncoat sniper and the other had the assault rifle. I literally couldn't do anything. I had to order one of the spartan units (UNSC mod is pretty good) just to breach this place, I would send a unit down with any assortment of weapons but before I could even get him to the ground (it was a pretty good drop) he was pretty much dead. In the fight with two dudes my spartan lost his legs, but luckily he has partially regenerating health. I won the match with a legless spartan with just a spartan laser as the machine gun got destroyed.