I like to use Call of Challenge AA on these mobs in my group as a warrior. Unfortunately it doesn't always work, so casting a bit early might give you a second chance to call them.
the scrourge's are all located at the far east end of the zone if you have levitate on go to the pit drop down to the bottom. then follow the tunnel to the east end. I found one corner at loc -833,-2257, -768 where a scourge and protector and a wondering stone golem were it was the easiest place to separate the mobs. with a full group and a good puller there are 4 or 5 more up on a platform close to here