Other than was has already been said, my experience is as follows:
Maybe you are doing it, maybe you are not, but managing aggro is very important as a Marauder solo questing. You need to let your companion take some of the damage for you.
Let your companion initiate (a dps comp, not Quinn, I used Jaesa ever since I got her), and burst one of the mobs quickly (you should take aggro from it after a couple of skills), If at any moment (after defensive CDs) you are below half health, go Invis, this will reset your aggro and the mob will get back to hitting your comp, dps slowly as long as your comp hold, if she gets low, burst again, etc.
This will work for any hard mob, even golden elites.
Also, more importantly, you are probably not using your Interrupt. most of the Elites burst damage abilities can be interrupted, sure, they can usually recast it, but it will buy you precious seconds in which your DPS comp will still be hitting them. This includes timing Force Choke to interrupt, not just using it whenever.
Lastly, for this particulat fight, I would go Berserk over Predation, not sure which one are you using, but Berserking with 6 rage built and just 6-spamming Massacre should down one of the mobs fast enough.
I dont remember how I did it, but I remember not having problems.