Watched the video on Tankspot and noticed the following comment:
"Actually, positioning seems to work better if melee and ranged and heals all stack where the melee are in this video...and keep one hunter where the ranged are...that way the pillar is always on the hunter and you can just have ranged switch over to parasites while hunter kites...then no one has to really worry about getting hit, and moving, and makes the fight less stressful"
The reasoning behind this is that:
1. Magmaw rarely targets (if at all) those right next to him, therefore he will focus on the lone ranged with his pillar of flame. when this happens the hunter drops frost trap and the other range then nuke adds from the melee position.
2. Secondly and most importantly.... it means there is less movement to contend with, less possibility of mistakes and as the guy above said ...less stressful.
A chance for the GL to show his hunter skills