I think the zerkers RA style, like it was for a long time on a certain other server, may be borked here in a similar way. I had a zerker do this to my friar. Its a combination of using a slow 2her along with this RA style, which could be even worse if the go full berserker mode on you, potentially 1 hitting many classes. It should not be this powerful, actually far from it. I think this needs testing/correcting to confirm.
I believe the same type of RA ability from the Hero "Razorback Style" does the same amount of damage so the same could be said for that style as well, not just the Tundra style. Granted as you said, using it in full zerker mode would help with the damage since crit rate is 100% in that mode, but that's the benefit of the zerker....It is also a 1 time use ability and has a 10 min cooldown since it is a RA.
This was from a different post from someone else so I have not tested it myself. Also, it was tested on a dummy so I could be wrong about its damage. Schreon makes some good points about these styles in the thread below and i think if these styles were to be changed it should not be drastically changed