There is a video of Titan hard using only one tank, and 3 healers. Garuda kinda sorta needs 2 tanks, even tho the sisters don't do nearly as much damage as Garuda.

After that video, Idk about doing Titan with less than 3 healers. Was doing some massive AOE damage towards the end with rapid stomps. I think using duty finder for titan will just lead to fail all the time, because it doesn't have an optimal party setup.