Survival hunter
Lock
Ele shaman
2 warriors
dk
they have some AWESOME cleave. i think the main thing though, will be decreasing the amount of objectives to increase performance. dps is on the low side, i agree and this is the only converning factor. but looking at their members and gear, it seems like with more focus its going to sky rocket. but only trying will tell.
And trust me, having them stacked feels so controlled its ridiculous. Tank healing and taunting becomes a non issue and allows more space of the raid as the bosses are all stationary in 1 spot never moving.
However i do think the OP can kill with either strat if the DPS can pick it up and focus a little more, i just feel for "most" raiders, less mechanics = easier time focusing on remaining ones