well have you tried to run a 3 man fp with a comapnion or a 2 man 2 campanion one yet. Its doable, but alot harder then anyone gives it credit for (but very possible)
At Rakata level... If the Tank & Healer are human, ALL HM are doable like that with the exception of LI. Requires a bit of tricky maneuvering and some direct commands, but can be done regularly (I did it as an experiment, ofc, a competent team of human players should be faster on most cases).
EDIT: I mostly did this right before 1.2 hitted (And haven't dared to attempt LI, still
), btw... Not after 1.3 with the newly nerfed HMs, which, in theory would make this easier.