I got my time down to 9 minutes from beginning to end to restarting and ready to go. This was using a paladin. My problem was I moved the slaves around too much. I also started aggroing one pack with autoattack, dragging them to another pack and using holy wrath, then on to the next to use consecration in range of a fourth pack i could use that shield throw on. By the time these four packs were down my aoes were off cooldown and i could start the cycle again.

After reading a hundred posts about powerleveling on here with bits of useful info scattered amongst them, I learned the slaves only needed to move across the little bridge near the entrance of the instance. I also stopped killing the last two bosses since there is too much walking (with no killing) involved in getting to them.