I think most people do this for Garuda and Titan as DF group never seam to be good enough to defeat either Garuda or Titan and people are wanting to complete there relic as fast as possible.

personal I would try for a pick up group in Mor Dhona as I have managed to find a great group to get me though Garuda.

at the moment I am using DF to learn the Titan fight before trying for a pick up group