Here’s something to think about. In the real world, we have cities like Tokyo which aren’t far off from Solution Nine as well as small rural towns, tiny villages in places like mountains, jungles, etc. and everything in-between. Depending on the context of what Solution Nine ends up being, I think it could be fine.

This type of technological divide also isn’t new to Final Fantasy either. Esther from FF8 is one such example. The empire from FF6 is very different than the random medieval villages that sprawl the majority of other locations in that world. Compare Archades from FF12 to the nomad village, or Eruyt Village.