Tried Heroic Butcher last night and we definitely didn't have the dps/heals to down him, even with perfect execution. I will say though, I took WAYYY less damage than both other tanks, and was much smoother. EB was great for avoiding the cleave, and mastery stacking felt amazing for tenderizer stacks.
It was pretty ironic watching my DK co-tank get smashed in to oblivion while I still had CD's unused.
We eventually tried a 3-tank strat where we rotated every 1 tenderizer stack and 1 tank always moved away. That seemed to lighten the damage dramatically.
One final note though, we did this with around 14-15 people and 4 healers so I'm not really sure that was optimal. When we did normal mode with 11 afterward, we eventually had our top healer go to bed during Tectus, and surprisingly the damage with only 10, despite losing a good healer, seemed MUCH lower. It was very strange, and we may play around with the group numbers as a result.