MT -> Garuda+Suparna | OT -> Chirada:
MT will have to manage double WW and later on Spiny Plume too.
This means high dmg spikes on MT and high risk of wipe if either MT or healer make an error.

MT -> Garuda+Chirada | OT -> Suparna:
MT still has to endure alot of damage from WW+Downburst and manage Spiny Plume.
Only viable if DDs are cappable of killing Suparna before she can use WW.
High risk of wipes from errors again.

MT -> Garuda/Suparna | OT -> Garuda/Suparna | DDs -> Chirada:
MT and OT both have only 1 mob to tank which makes swapping Spiny Plume eaiser.
No problem if Garuda and Suparna switch places between MT and OT.
DDs+healers stack and burn down Chirada. Slipstream can be dodged and Downburst damage is split between hit characters.
Less dmg spikes making it easier for healer/s to keep everyone up.
Less risk of wiping if someone messes up.

I prefer the last method.
I don't understand why the MT and healer/s should carry the whole burden of this fight just because it's "common tactic" or "it's shown in a video guide".
And people who say "only bad tanks/healers can't do this"... why can't DDs dodge 1 attack to make the fight easier for everyone?