You can pretty much just blow all cds on the first add, second add should die easily with higher stacks. Then 3rd onwards you can blow the add up in melee instantly with the help from your other tank. You never need to reset stacks, you can let the dpsers get the first charge on pull You can be full parry gemmed, i dont really see point in mastery/crit. Full crit makes you too squishy to make up for the +5% ish up in damage.
Prot warrior is so OP in siege adds that you shouldnt have problems if you execute it right. A common mistake i see is the addkiller standing ready for the add, then taunting it and trying to kill it.. I just tell them to stop tanking alltogether if theyre so daft trying to kill the add with zero vengeance
This is 25man, dont know if the add is harder or easier on 10man.