Nope, just have to grind out THM/CON to 48 each. Obviously not as powerful subbed... but not so sure I would spend all that time leveling them up just for that purpose, since they will be changing the armory/battle system very soon.
I was leveling other jobs just for their higher rank traits to use on GLA, but now that everything WILL be changing I'm just going to level up a job I actually want to.