Yeah you're overlvl'd for RFC lol; the key is to kill the Caster troggs first. At low lvls, Casters do INSANE damage for their lvl(like the Defias Pillagers inwestfall used to do over 100dmg per fireball, which is enough to 2-3 shot most chars at that lvl, Blizz nerfed them recently down to about 30-60dmg); the same is true for all casters for quite awhile, they put out massive dmg in exchange for their lower hp/armor; burn them first. Always. Melee are gnats to a tank, but Casters burn through everyone ;p

Going by your setup, have a mage sheep one(Preferably a Melee, Casters have to die FIRST in 90% of cases; if sheep breaks/mage dies and that caster comes un-cc'd you're fucked, better to destroy it early and deal with the easier-tanked melee later) after the pala pulls(Manually set his target pre-fight then fix it after sheep, or use a Sheep Target=Focus macro and MANUALLY set the focus per-pull then give him the normal DPS target, no target switching needed midfight), Priest shield the pala pre-pull if he has it since you won't be rage-starved by it, put a renew up too(may require a Fade, but that's what it's there for); Fear one if you have the room, I think you have it by now, if not, consider Curse of Weakness instead of Agony to help mitigation