Well, sticking with the 2 toon setup you have, it'd be a great grind. Warrior's #1 problem is lack of heals, and you have a healbot in tow, taking almost all of the frustration out of leveling a warrior. You can set up macros for the druid to help out with spellcasts, and heal the warrior when he's running low. Non-stop grinding as your main damage source, an arms/fury warrior never needs mana if his health is full. In fact, Warriors are better when you can go from fight to fight quickly to keep as much rage up. I've never played with it, but I'm sure someone could tell me if Warrior charge breaks follow.

Playing the druid as feral could be problematic, it's never easy to melee-box.