I have a 70 Hunter and a 60 Warrior, both on separate accounts (yes, same name)

I've been fooling around with Dual/Tri/Quad-Boxing and was wondering how to level the Warrior.

What I'm thinking is Quest Boosting using the Hunter as the "alt" and the Warrior as the main. Should they be grouped or not? Also, is there a way to level that would be more efficient than this?