I wasn't beating triple healer teams until I pushed my spell damage over 700 with 3 shamans and 800+ with one shaman. I also use blood fury. Suppose I do kill a guy that screws up and lets me unload a lightning bolt volley followed up by 'IWIN', the 3 healers triangulate the corpse and really run me ragged trying to res while the last DPS puts preasure on my healer.

I haven't cracked 1600 yet, and triple healer teams are causing me and my partner the most headaches.

Your method is correct, you gotta get one LB volley to land followed up with 'iwin' and hammer shocks to finish the job. It's probably your spell dmg vs. their resil / hp stopping you from taking one out.