I've had similar problems in BfE T2. I've beaten T2 with Blood Rage when i was level 85. My kin is now practicing for T2CM at 95. We have a guard on one troll, a warden (me) on the other and another warden on the adds. We used the same make up when we used to run it at 85. Actually we took down T2 with two wardens tanking.
My Crit Def is 72%, BPE maxed (I use a sword so my parry is at about 28-29%) and morale is 30k with buffs. When the troll got the +200% damage buff some times i got hit with consecutive 23-25k hits. The mini assigned to me could not top me off fast enough so i died multiple times. This happened at least twice during our each of our attempts. While i was down one of our captains took over for me and he had no issues.
It seems that Guards and Captains are better choice tanks than us in both multiple and single boss T2CM tanking. I am also sure that nothing is being done to address this problem by the Devs because their focus is elsewhere. New raids are not coming out this year and possibly not next year either (or ever again) so there is no need to address one classes problems tanking top tier raid bosses when there are 2 other classes that can do so easily.
On a positive note, i never get one-shotted in Big Battles! Actually, wardens are the best possible tank choice for Big Battles. O.o
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