And interestingly enough if you map out the classes/jobs you get this nice little pattern with the original job requirements...

Gladiator
Marauder > Warrior (GLD lvl 15 needed- check)
Lancer > Dragoon (MRD lvl 15 needed- check)
Puglilst > Monk (LNC lvl 15 needed - check)
Samurai
Dark Knight

It's almost like they planned out his first set of jobs because surely it's not a coincidence that the secondary classes needed at level 15 just so happened to be his last class. And you can see why archer sticks out again here being the odd one out.