I did this at 49 like most other people, and I have to admit to a certain amount of arrogance going into the fight. First round TKO, oh well. Got back up and now that i had a good idea of the situation, I found that dps'ing both was the best way to win. I'm an assault vangaurd, and found it best to start out popping my power relic, then using mortar volley, and then tossing the stickey grenade in. Both mobs were at 70% at this point. As they started to heal, I would interrupt in whatever manner I had available. Harpoon one, cryo the other, and then riot strike the one i harpooned. I put my incindiary round on them both and kept using all my aoe's and kiting around that middle pillar. If you damage them both, they only heal themselves, typical imps, then just keep ur dots up and using sticky and mortar volley. There is a HUGE amount of burst in assault, I highly suggest speccing assault for that fight.