I very much doubt you could run a flashpoint at "level" with (4) Marauders let alone (2). Yesterday night my Marauder/Sorcerer team hit level 20 and completed Balmorra; I decided to try the Heroic (2)+ when you first arrive on Nar Shadda.

The only way I was able to pull this off was using my CC whirlwind on the Elite, burn through the hard's and then go after the Elite; many times I needed my Sorcerer to bubble and heal as some pulls have (2) Elites.

Perhaps if you WAY out leveled the Flashpoint to the point of why bother 2-boxing it would it then be viable