you're ignoring his mechanics if youre dying that fast. He almost always starts off with an immediate incinerate, which destroys anyone. you have .5 seconds to interupt his cast before a shell is launched. He does it approx every 12 seconds.
Dont go in with 2 melee dps.
Why should a group be forced to take certain classes?
We tried to do this with two melee and a Jug tank and couldn't get any better than 50% on the first boss. The fight has way too much going on for a melee group to be able to complete it on HM. We wiped for hours and ended up going into the red for durability twice before just giving up.
(Everyone was in almost full Rakata)