Doesn't even need the job system to nerf ARC, auto-attack could easily do that. I'd still play ARc/RNG whatever it's supposed to be I just love ranged attacks
And don't worry grimlock, MAR will definitely be a DD class. SE has definitely realized the issue with PUG and MRD being tank/dd's and hence the job system is coming out. I'm going to guess since SE states that classes will be more solo oriented that certain jobs will have attack boosts and defense penalty to make them deal much more damage, while taking much more. Therefore, being better for group play with a designated tank.