My opinion is to use a ranged class. If I was going to pair someone with a pally, I'd most likely do a hunter and use misdirect a lot as a means to pull mobs into melee with the pally easilly. Don't forget to turn growl off. The casters will go down fast enough with just the hunter. Another good possibility is to pair the pally with the death knight and make generous use of death's grip. Having levelled every class, by far the pally is the one I had the most pain with. If you're considering using RAF, I'd strongly suggest using as much RAF on your pally as possible and go w/ ranged DPS classes for the actual levelling as much as possible or at least pair melee classes w/ a ranged DPS to minimize the melee pain.