Account 1....70 Pally, Account 2......70 Rogue Fire Mage, Acount 3....RAF from 1, Acount 4......RAF from 2

I created 2 RaF accounts, each one linked to 1 of my previous accounts. I am running 4 Shamans...about lvl 37 now doing quests. I now realize I can split the group of 4 up and do SM with the Pally boosting 2 linked accounts, but with the other 2 linked accounts.....should i boost them in SM with a Combat Rogue or a Fire Mage?(i am guessing the Mage) I would also guess i would need to respec the mage to either Arcane or Frost to Aoe better....but Ive never used either of those specs yet? Any ideas on Specs and a good plan to Aoe in SM with a Mage?

Great forum, Ive lurked here for a long time reading info that helped me Lvl both the rogue and mage with my Pally.