I put the two main buffs on the same buttons e.g. Priest/Mage first button has Fortipoop/Intellect, second button has Inner Fire/Frost armor. I just broadcast click those two, then use Clique bindings on the group healthbars to buff everyone with Fortipoop and the priest with Int. Only gets fun when you just learn a new rank of the buffs and can only cast two of them before OOM.

Don't overthink it.