So i remembered this was a thing. It says Nymian but it is quite obviously made in the same style as the floating Mhachi city; Dun Scaith.

Did the devs botch up or are they trying to tell us something?

Crazy-goggles on!

What if there only ever was one floating city? Created by nym, taken by mhach and repurposed to house the Mhachis?

This would explain why the floating city on La noscea is just a huge hole with some ruins on the gound and why Dun Scaith is just a big empty somewhat touched upon city. Did Mhach simply steal Nym tech to survive the flood? I wouldnt put it past those pesky lalafells!