My guild uses a DPS-switching strategy, where the DPS swap sides after every DD. Each DPS pair consists of a melee and a ranged, so that there is always one ranged DPS in each shield (we run twin shadow tanks and yank the explody trandoshans to be killed from afar). Since we DPS swap, we're usually lazy and just allow the second DD to go off, but there have been ocaisions where we push it (just for fun) and skip the second DD. Based on the numbers we've seen from parsing when that happens, it looks like the DPS requirement is in the range of 1900 for both DPS on SC if you want to reliably skip the second DD. Our two melee DPS parse in the 2-2.1k range, while our commando parses around 1950 and our sage is 1800-1900, so it really just depends on how we feel like doing the boss.
I'd say that, in general, DPS switching is the most lenient strategy, especially if you have at least 2 ranged. The burst requirements are less severe, and mistakes are more recoverable. Once everyone masters the positioning and movement requirements, this boss becomes a pretty easy one-shot.
Why? What is the point of doing this? I'm really curious because I just can't work out the whole thing at all. Your ranged DPS parse similar and your melee parse similar and you have one of each in both pairs - so what's the point in switching them around?
I'm sure I'm missing something here as I'm not the sharpest tool in the shed but can't figure out what is it.