I seem to remember someone making a very good post on here about how to insta-pull SM. It was a real forehead slapping "of COURSE!" thing that might help

You target the area boss (with a macro if you cant see to click) send in your Voidwalker/Water Elemental/Pet right into the the bosses and BOOOM, you insta-pull all the trash in the area. Proceed to AOE & profit before moving into the next boss area.