I've played through as both a Defence, Offence and pure Force user.. no matter what build; I still had alot of HP and FP and could easily wipe the floor with anyone in no time..
in essence, it doesn't really matter.. once you're lvl 20+ you can take anyone down.
Edit: although I found the pure Force user to be the most effective.. he could spawn Force Storm (even as LS) without it showing on his FP bar - and kill everyone, but the "bosses", within 2-3 tries.