Well guys, thank you for all the answers!

I've got to say that i don't get where is the problem then, if you all say that is doable like that, and even without LB... (we keep failing at that phase.. if we focus the Boss we get to phase 4 with an Add.. if we focus on killing adds we get to the third HF and we wipe)

The ilvl is really high, around 120 average.

I think we'll try to go for Solo Tank and see where we get

any other suggestion is welcome!