To the OP:

Let the warrior do the slugs.

Here is how we did it on our first kill, I was a little nervous, messed up where I could have avoided a hit or two but in the end this worked out pretty well:

http://youtu.be/cG4zcgtsq9I?t=5m32s

5 Wrath Stacks, Steel Cyclone attack between the slugs when they spawn and another Overpower while running to your camp should be all you need to get emnity on all slugs.

Better pop Thrill of Battle and Vengeance when the Slug grows as it hits HARD.. The rest depends on your DPS and Healers.. When you get another set of three slugs, Overpower them a few times and kite away until boss is dead..