kola
It would not be long that the Alsinans grew wise to the CI heavy trooper's operations. After losing a few men to their grenade then sweep of a room modus operandi, they began to lay traps in the rooms, where, once the grenade detonates and marines go into the rooms to sweep them, an Alsinan mercenary would come from behind, having quite the clear indication of when they've gone in what with the bright flash of light or pressure wave booming throughout the nearby areas, and gun down a marine or two before ducking out of the room to retreat, waiting for their response to come and pass.
As the push of the CI heavies is engaged in the "wall" of Alsinan men, the remaining heavy troops envelop them from behind before launching their all-out assault on them, firing till their guns go empty into the heavy armor, targeting any weak points like knees, the neck, anything BUT center mass. Grenade pins are pulled and thrown, and the sandwiching of the heavy troop's main push is preventing them from escaping.