Kromrif Spearman  

If a raid wants to kill these, everyone has to know that. If a raid does NOT want to kill these (since it is not necessary to do so to win) everyone has to know that or these will be problems, since these guys summon if you aggro them. If you are going to kill them, take them out during the first wave, when it is easiest and there is the least amout of pressure from more mission-threatening spawns.