I think a better way to do this is a rating system. 1-5 stars. Essentially you have the option to rate each player and it calculates their average rating. Essentially like how shopper reviews are for websites like Amazon. This rating will of course be invisible to all but the player themselves or not at all. From there people of a similar average rating can be grouped together.

To eliminate the problem of say for example a great healer switching to a dps class, which they don't play very well getting in dungeons with highly rated players, the rating can be based off either individual classes or entire roles. Meaning one can be a 4.8 scholar but a 3.3 ninja for example.

Of course people can always have the option of queuing with those whose ratings are below theirs. Sometimes people want to get a run over with without being delayed and some people just don't care.