So I came from a group of 6 tanks and 2 heals, and later 4 tanks, 2 heals and 2 dps. Granted not as efficient as the typical accepted setup, but it works well and almost as good. A bunch of RF groups are sitting there on the list STILL waiting for that elusive 1 or 2 dps for nearly half an hour, while there are probably a lot of tanks and heals who might be willing to even beg for a spot on a light farming squad.

Really, rather than wasting your time strictly looking for that last dps spot, that last spot can go just as easily to a tank or heals. A1S is so easy you'd barely notice the difference in clearing speed. It's way more efficient to use a slightly less ideal setup than sitting on RF doing nothing.