Geomancer was in the Astrologian questline, but I never saw any healing spells used. On the other hand, Kyokuho was tanking that fox spirit like a boss! Between that and the protective magics, it's possible SE is setting the job up as a mage tank? (I hope I hope I hope)

I'm probably reading too much into it, though; it wouldn't be the first time that SE has used unlikely jobs as tanks in solo instances.

It did seem like the questline was promoting AST+GEO as a team - and what team is more natural than Healer/Tank?