You said you can pull enemies into your range, I pointed out you can't grip bosses. That's not moving the goalposts that's pointing out grip means fucking diddly on raid bosses.
Btw just so we're clear, are you stating dks don't perform poorly on high mobility fights?
You didn't look at the wrathion fight? You know that fight we're discussing, because it's literally the first high mobility fight in the current tier of raid content? Also, did you look at the prepatch data? Do you not know how to use warcraftlogs?