i got to thinking bout it, and it would be extremely cool if we got advanced versions of each job. so people could actually see what a "harder" more complex unique job system would look like. make them levels 1-50 and let people do level 1-50 content with them and group up with other advanced job users. you would be learning advanced versions of jobs and some newer more complex jobs from each city state leader
dual wielding greatswords like a berserker job learned from raubahn. after we get the sultana to make him teach us ofc. basically alot more emphasis on harder hitting combo finishers and multihits (prolly an advanced WAR job most likely)
merlywb teaching us that old dogs can know new tricks with dualwield pistols/other more piratey skills like throwing out an explosive barrel that explodes after a set time. the pirate job
Kan-E-Senna teaching us about how to be an elementalist job making full use of the elementals and the elements themselves. more emphasis on debuffs and buffing and would still be primarily the main healing job. think advanced WHM.
aymeric could teach us how to be an even better shield for our allies and protect them from everything the guardian job. basically advanced PLD. but a real caster tank no melee just hard hitting holy spells and more long range support spells. if we wanted to get wacky it could be a dual shield job as well
lyse could teach the ways of the ala mighan fist the abbot job. a play on real life monks where abbots were basically the head monk. also yes rhalgr would prolly intervene since we know about them now hence why you're able to push your limits past that of a normal monk. with more emphasis on meditation channeling combos, and hard hitting single punches, and summoning giant fists to unleash devastating combo finishers
vrtra could teach us how to further our progress with the dragon inside us the azure dragoon job. the reference should be self explanatory. with more emphasis on using aetherial claws and jaws summoned from the tips of our spears and maybe a bit of fire breathing as well idk.
for crystarium we would learn from Lyna how to be more wild and creative with our dance moves in combat the entertainer job. honestly i wouldn't mind learning skills like we seen in that one DNC job quest when we were learning DNC and she was pulling out all sorts of crazy moves. thanks to the wild and unpredictable nature of this "wild" dancing every hit has a chance to unleash a different elemental hit on an enemy (debuff or DoT). and instead of being forced to follow a rythym or pattern while you fight each GCD leads up to a dance finisher. think like mudras or PB on MNK but all the time.
eulmore we would learn the engineer job from chai-nuzz. think a more advanced MCH but with more emphasis on turrets and machines. a less active playstyle and more so like a minion job so to speak where you actively control each contraption. and prolly have an ability to have them all forge together to make a mech that you can hop in for their burst window,
sharlyan is still a toss up but i think the twins dad Fourchenault Leveilleur would be our teacher. now ik they wouldn't wanna do an advanced SGE so i was prolly expecting him to be an advanced SMN/SCH teacher. idk a good name for the job sorry. learning under him we are able to summon multiple egis at once and access more devastating comboes based around the ones summoned. so if we have leviathan and ifrit together we get a fire spell and water spell that after using them they come together to give us scalding steam our big summon finisher then the egis dissipate and we have to summon new egis.