I see this as the ability to have options. one can slap on the job Paladin to be a more effective tank and be great in NM battles etc. However when doing regular mobs, or lower level solo nms it would be nigh impossible because of low dps. i like the brd example from ffxi. With this new suggestion an arc can now slap on brd and be invited to ifrit battles and slap on arc for other types of content. Versatility is always welcome!