The problem I've seen most often after running with many Garuda EX groups is MT died from double Wicked Wheel. This is 95% cause of the wipe. I never play tank so I don't know what to suggest but if MT can't live through that we're done. Another minor problem is some group just don't have enough DPS to kill the sisters fast enough during tornado phase.
Yeah, surviving that double Wicked Wheel basically requires your tanks to be on time with their cooldowns, the DPS not to be slacking so the Wicked Wheel happens at the right time, and the healers to be timing their Stoneskin/Adloq as well as keeping your tank topped off.
Personally, I like the Triangle method better as it removed double Wicked Wheel entirely from the fight. But not many people know how to do that method. :\