I got Dragoon as my 4th Job and I just got the Submarine. This run has been hilarious. Spent time farming Twin Lances and Ruby Rings. About to get the Chicken Knife. I hope that my 5th job is good enough to sub out Monk (please be a spellcaster) because Monk is an awful Job, and Thief is purely for Steal. Dragoon isn't going to do much unless my 4th job is Mystic Knight as well.
tldr: Ninja is carrying the hell out of this run.