After so many failed Garuda Extreme runs with randoms I can't help but think that a good tank is more necessary. I imagine a healer would be easier to educate if they kept failing plus the party can run off of a lone healer for at least a while afterwards, whereas off-tanks cannot sustain both roles in most trials.
Characters: Andre Winter (Hy'ur) / K'nahli Yohko (Miqo'te)