It's also important to note about LR-5, which no one's guide ever seems to do, is that it has a 3-minute "soft" enrage mechanic, where it belts out full-sized energy fields at a retarded rate and nonstop fire from the grates.
Bringing even one melee is a huge liability for that fight in terms of meeting the enrage, kind of dumb.
I've done it just fine with two melee DPS using the kiting method (in a pug no less). The group just really has to get those interrupts on incinerate if he's standing in the AOE, which usually falls to a DPS to do while the tank waits in the next position.