I'd hesitate to lump an AST or a PLD in with the likes of BRD/MCH simply because of the differing methods if their utility. PLD has an AOE 10% shield that they rely on someone else to proc and two spells that they're hard-pressed to actually get off without constantly being interrupted. AST has a plethora of different buffs but no real control over their use like BRD/MCH do.

Not saying that the discussion of how to implement future jobs with nifty utilities isn't fun, I'm just not sure PLD/AST can be considered "support" when one has extremely niche support and the other has support so unreliable it almost seems tacked on as an afterthought.