From my experiance as healing raids the pala is best to start healing on pulls cause they can bubble after the 1st heal and just spam for all there worth untill the priests take over.
1 shaman to heal the raid
1 pala to heal tank
2 holy priest for rotation healing
Id ether take a shaman or a paladin unless you need the extra healing
id also use 2 healing buttons 1 full power heal and 1 2 ranks below as main heal
50/50 mana bar watching on priests is a good way to rotate healing just set a macro to target other priest and watch the mana bar. at 50% you take over by assisting the 1st priest. 1st priest must only stop healing when he / she sees that heals are going to the tank not before.
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