Whats your guys light level? And are you using Weapons of light? I was with a group were we had 1 290 and 3 293s, 2 295s. If one of us went down, we could only flinch him with WoL. If 2 or more of us died, we were screwed. Even with all 6, If you missed a sniper shot it could mess it up. The burst damage to get him to flinch is in the tens of thousands range, so it is no easy task. Even if you have a strong sniper, your light can drag your damage down too far.