Well, the triangle method I do doesn't even require us to lb chirada, we don't even bother, since the stacks due to the tanks swaping positions by running to the other tank's position take care of that nonsense and the other problem your describing doesn't even exist since only the person who has agro dodges slipstream. The only time the other dps move is for 3 reasons. Downburst is coming which is when they stack, they get friction aoe on them, and when chirada dies so the melee go and abuse the now vunerable surparna.

I've done this with very nooby players and melee with average gear, ilvl 75ish-ilvl80. We had more problems with spiny plumes ie dps kept killing it too soon rather than pulling and surviving chirada's downburst. Infact on a test run a dps actually screwed it up died and the healer just rezed him, The dps loss was negiliable and we were able to STILL kill both of them with plenty of time to spare.