I've been sniping from that spot since I was able to go into the highest vanguard Strike runs... If your Sniper (any Sniper, not just Ice Breaker) is leveled out enough, the headshots on the Priest will rock him back and keep him from attacking. This allows your teammates to pour on the damage by the bucketful with any other weapon of their choice. In fact, if you and another Guardian with Ice Breaker can get the timing down and alternate headshots, the Priest can be taken down without ever getting a shot off. So your claims of "cry cry cry I'm doing all the work while those cheap bitches with snipers... cry cry cry" just falls apart when actual intelligent thought and a bit of tactical knowledge gets applied to your argument.