Geomancer

[AnotherPerson]

omitted for character limit

It's probably because at the beginning in which Geomancers were introduced to the storyline, it was hinted at how similar their professions are. AST's nocturnal barrier magicks mixing perfectly with the barrier of a different discipline also reinforced this concept that they are compatible in discipline and probably close to the same origin - which is why Kyokuho plans on returning to learn AST after he settles the mess in Kugane to continue to supplement his understanding of the stars with his Geomancy.

His grandfather was mentioned that he was refreshing the barrier up often if I recall correctly as he had to have been in the area to do so if he was not using the forbidden technique to constantly maintain the barrier. Barrier magic or healing both fall under the healer category to be honest. That's what Scholars/Astrologians do - create shields.

Technically speaking, they already reworked DRK to be more similar to Warrior for the sake of balance and got rid of Dark Arts spam entirely so I can't say for certain. DRK's gauge works the same way as a Warrior's gauge. You can see the complaints in the tank forums about how gameplay for tanks there.

Two elemental healers isn't a problem as long as their kits and gameplay are unique. The main thing is that their lore and their gameplay can be differentiated from each other. WHM communes with elementals to use the power of nature. Their heals are powerful and constant, and have plenty of regens and oGCD heals.
Geomancers access the elements directly but have it more heavily aligned to whatever the land is like. This can be directly shown through gameplay by making Geomancers' skills change on a gauge and gain an effect based on the lean of the current elements. Gameplay wise it'll be entirely different because Geomancers will be heavily dependent on their gauge to function and this causes a variety / lack of constant effects. Their ability to heal/support the party will naturally be different.

Of course, this is just the example I'm using. It'll ultimately depend on SE and how they implement the job itself, if they do plan on adding Geomancer. I play healer often enough to consider myself a main, and something like this would at least seem appealing if the gameplay is different. Unlike conjury, the Geo storyline won't be involved with elementals to use their power, but probably more aligned to the understanding of the land itself and more towards Astrologians' way of studying the stars and divining its secrets. In that aspect, the storyline will definitely be different. I expect a larger part of the story will involve Feng Shui instead seeing how big Feng Shui is in Eastern culture and Geomancy/Taoism. It's essentially a different approach to the same elements with different underlying concepts to focus on.