[QUOTE=Bixby;1466730]To progress in party content (including the dungeons required by the main story) much past level 30, you're going to need to unlock job(s) for your class(es). Conjurer just isn't a good enough healer, Gladiator isn't a good enough tank, etc. Unlocking a given job requires a specific combination of classes leveled. The jobs are also limited as to which classes they can pull cross-class skills from. WHM can only use skills from ACN and THM, for example.

It may help to not think of the jobs as class 1 + class 2, since they don't really play that way. A WHM isn't so much CNJ+ACN as just specialized CNJ. The WHM job quest just has a requirement of having ACN to 15, and you can pull skills from ACN. But you don't really add in play style elements from ACN.

It's a bit ironic that the most useful whm cross class skill isn't from the must do Arcanist :-)