I'm not sure if you're aware of melee attacks breaking /follow, but it'd be much easier to have the warrior as your main for dps/tanking, and using the paladin as a healer/buffer. Personally, I'd get the warrior & paladin equal to the shaman/mage at 42, then rearrange the groups:
paladin / mage = prot/aoe spec paladin + aoe-spec mage = massive aoe fun.
warrior / shaman = arms/fury warrior + resto/enhance shaman = good warrior buffs + heals. (this combo used to be more fun when windfury totem would proc extra swings..)