The 2 piece set bonus from the Onslaught protection tier, is currently bugged, it provides 170 PERCENT buff to Commanding Shout, I guess the devs forgot to change it when they changed the way the buffs work. Just putting it out there, as much as I enjoy rolling around with 1.11m HP during raid testing I am guessing it's not suppose to work that way on live.
Providing images for clarification;
https://i.imgur.com/vt9yv.jpg - Without 2piece
https://i.imgur.com/zdiHs.jpg - With 2piece
Enjoy it while it lasts
Credit to Taumma from MMO-Champ Forums.