I can't imagine having a rotation of 6 elements, my hotbars are crying at the thought.

The Geomancer spirits in Swallow's Compass seem to be okay with just the four elements of Water, Wind, Earth and Fire. The four colors used to seal the door to get deeper into the dungeon.

There is a screenshot of part of the Geomancer dedicated page in the second Lorebook floating around that talks about why Othard Geomancers only use water, wind and earth. Which is why I assume Kyokuho's title only refers to wind and water (personal preference maybe?).

Being the only living decedent of the last Geomancer, (hell that's a class npc storyline if I ever heard one) and him being the one that is starting the school for Geomancy, this could be his own personal take on the whole thing.

Kyohuko we have given you the few summers you asked for to start this thing, where is the army you promised us?