I've ran this so many times with two Marauders by now and I never had to move the boss around because they actually paid attention.
This. PLEASE no more nerfing to Lost Island. It is already easy enough considering it's the "hardest flashpoint in the game." As far as mdps go, our guild actually prefers to run this with 2 mdps because it makes it so easy to aoe heal. They just need to pay attention.
1. mdps shouldn't be standing at 0.0m away from the boss. Get them to max range.
2. For Sentinels/Marauders, Force Camo is your friend when you get the circle on you (speed buff).