Keeper of the Moon culture.

[Catapult]

I'd assume the Miqo'te were one tribe prior to their migration to Eorzea in the Fifth Umbral Era. Once the ice thawed up and the land returned to 'normal' they could have then split into the different tribes and settling in the different parts. Seekers in the Sagoli Desert and the Keepers in the Twelveswood.

No, we've been told the Seeker of the Sun migration was 26 tribes of seekers.
The Keeper of the Moon tribe may or may not have happened at the same time, but would have been a different migration group by the looks of it.