Well, since SE wishes to go with 'easy' fixes - why not do the same idea here: Disallow any non-job classes (IE: LNC, MRD, PUG, THM etc) to queue in 50 brackets. This will help solve inbalances without nerfing Jobs. This way, for example, WAR won't have to receive any significant nerfs whilst dealing with the overtuned MRD.

I'm sure it was not intentional for non-job classes to be outperforming their successors.