If i were levelling 5 druids I would probably go with a bear tank and 4 moonkins.

As others have said, equip the moonkins with cloth for the int and spellpower. The bear tank solves the issue of the mob running for the moonkin.

The closest I got was running with 2 mages and a bear tank. I would run towards the mobs, drop the slaves off follow and hit the mob with the bear a couple of times to get initial aggro. With just 2 mages the mob died fast, with 4 moonkin it will only take a couple of rounds of wrath spam.