The last trial fight in Heavensward... The last time I did it we had 3 bards. That was the slowest I have ever seen that fight go, so I imagine the 3xMCH setup would be equally slow. Pre-50, MCH damage didn't seem noticeably terrible or anything. I'm planning on taking MCH up as my next job as it interests me despite it being what it is.

I will say though, if they use their knockback, I'll just switch to a new target and ignore whatever they want to slap around. If after asking for them to stop, they keep doing it, I'll just initiate a vote kick. I don't really have the patience to see the mobs flying all over the place needlessly.