One thing that actually can work, is 4 hunters + a healer. I once leveled a group like that through instances to level 30 something, it wasn't really very difficult, there was so much damage going out that stuff tended to die before the pets got chewed up. The pets just chain taunt, swapping agro, and if they die, you have a mouse over res macro. Healer does what it can.

I don't know/think it's ideal, but, it worked for me in vanilla in an entertaining way. Likewise, a warlock would work as well, as a voidwalker is an even stronger tank than any animal pets.