Actually, my strategy with Vette is to have her attack the strongest enemy of the lot and have her take the first hit on the target. Then when the mob is agro'd, I jump in and take out all of the weaker ones before moving in for the kill on the stronger one(s) and getting the agro away from Vette. Then if I need to I'll use Force Camouflage to take agro away from me and put it back on Vette.
Vette usually gets taken down in the battle if it's up against several strong opponents at a time, but that's rare... in either case, I heal up with Channel Hatred after every mob.
It's worked extremely well so far since my Marauder has been SEVERELY underleveled compared to everything she's faced throughout the entire game so far.... but I still manage to take everything out with Vette right there with me.
But yeah, from my experience with the Marauder, in groups they're definitely the ones to mop up the weaker enemies since they dish out high bursts of damage and move very quickly to the next target.