Before I started 5 boxing, I had 2 lvl 70's on the same account (Shadow Priest and Fury/Prot Warrior). I transferred one to another account and I played them as a 2 boxing farmer team. With the warrior as the main and the priest tagging along behind.

It worked out pretty well. Usually, I'd charge the mob, put VE up with the priest, mindflay once or twice, while continually doing my thing on the warrior. The mob almost always drops after 2 mindflays. I switch it up and will only mindflay once and do wanding after to conserve mana.

I could farm quite a bit faster than just with 1 of those characters. It was pretty fun.

In my opinion, you either need to do a healing class with a warrior, or 2 straight DPS classes (locks, mages, hunters?).