How will future advanced jobs work?

[AceofRains]

If you guys were paying attention but alot of people sadly weren't ...

You'd have already noticed that jobs are already prepped for multiple different combinations.
After you take a base class and its 2 supporting class's skills, its not hard to see what kind of job best fullfills that role.

Ill use an exist job, bard as an example then go on to something else.

Bard is a support/DD. You run between party groups to give buffs while keeping your main target on the enemy. Normally, an archer is free to just wail away, but a bard adds the ability to keep party members fresh on MP, TP and Accuracy, not to mention if you've leveled THM, you get Resonance which makes it easyer to get songs to far members. And if you leveled CNJ Sacred Prism and Stoneskin further your support status.

Now take something like Dark Knight.
The best fit here is Lancer. Yes, lancer at first glance is just Dragoon, but think about it, Dragoon optimized Lancer for High Damage and quick disappearance via jump. Dark Knight is a job that eats its own HP to deal damage while having High draining potency, capitalizing on Lancer's life surge and power surge. In FFXIV, building a DRK would actually have tank Potential. I've ran into Lancers tanking before so I wouldn't rule it out. While your defense isn't great, you have the ability to drain massive amounts of HP and sustain your life. The two supporting jobs that best fit for Dark Knight are Marauder, and Thaumaturge. Marauder give access to provoke, blood bath and foresight, making it increase its tank potential. Thaumaturge gives way to Dark Seal, Necrogenesis Fire and Thunder. If I developed DK I would give it Drain, so you use Dark Seal with Drain to Increase Accuracy of Drain, Fire, or Thunder. Also use necrogenesis for increased self heal sustaining. Fire and Thunder also will give an edge when fighting mobs weak to those elements.
And so yeah... That ladies and gentlemen is the essence of a Dark Knight.

If you want to know how a new job would function all you essentially have to do I make one up and think of the mechanics.