Use mez in Nest missions. It's your best tool for splitting mobs there, until you get in too deep where some of the golems and corrupted drakes are level 74 and higher. There you'll have to get a bit more creative (snare works wonders.)
I can singlt pull Nest missions with very few problems at all...just the odd time where I get three mobs chasing me and they all resist mez :P Kite, kite, kite, mezzed one phew....kite, kite, kite....mezzed the second yay...drag away, fade, bellow tag and win. Fun stuff.