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.
Really not to bust the OP's guide here. But here is our guide with a melee dps with his soft enrage timer. Yeah we beat it easily in tionese/columni gear also.