To be honest the jobs are all balanced pretty damn well. The reason it looks like they aren't is because people don't actually use jobs to their full effectiveness. A good team with all the different jobs using each ones unique playstyle can ruin the chances of enemies doing damage. SMN is always said to be broken, but its not so much broken in my opinion as that people just are bad and I bet if you took a real look somehow at PvP I bet over half the people don't even use their PvP skills (like purify).