I never liked Protection Warrior in 2's. If I were you I'd switch to Damage if you still wanted to go in the 2's bracket but if you want Protection I recommend 3's.
Healing/Tank = High survivability, low damage. (In this case your healer will go out of mana because you can't kill the enemy fast enough so in the end they're just hitting a wall that isn't doing much back.)
Healing/Damage = High damage, medium survivability. (Best out of the 3, the ratio of heals:damage is nice, not quite as easy to survive as Healing/Tank but you have the damage to be able to kill your enemy.)
Damage/Damage = Very High damage, low survivability. (Burst scenario, quick damage, if they don't die within the burst time that you do, you're screwed. No heals = low survivability meaning you have to kill them quick and fast.)