We can put grob'thok i guess since it is possible to land all 5 like you said. Not sure about Nefra though, and definitely not possible to land all 5 on draxxus. sabo can land all 5 on corruptor zero if your raid tanks and pulls the adds on a corner, which is what my guild currently does.
Yeah Nefra is a little iffier. I personally don't like to roll around in that fight cause of the red circle. Far too many close calls for my blood.