My main issue with this is how multiple classes would affect it.

Someone can be a 90th percentile Ninja but have no idea what they are doing on Scholar, so would they be paired with people who know what they're doing and expect others to do so as well, even if they queued up on a job they don't know how to play? That might make for unnecessary toxicity.
Also it would just divide queues and those are long enough as is for certain classes.