A New Realm with new Threads (Gear Styles that should be around in ARR)

[Mudd]

All the stuff from FFX/X-2, FFVIII, and FFXIII comes from high-technology worlds. It just wouldn't fit well in this world IMHO.

It's better to look at FFI - FFVI, FFIX, FFT, FFXI, and FFXII for inspiration for this game.

10, and 12 are at about the same place technologically, if not, 12 would be ahead.
Even so, I can imagine some of the cities in 12 being similar to what we'll see in some Garlean cities.