If you take a look at the architectual styles of Morrowind (the game) none of the vanilla styles Hlallu, Redoran, Telvanni, Indoril or Velothi, even remotely resemble that of Cheydinhal. Indoril is the closest but it's region of influence is on the other side of the province (not bordering Cyrodiil). Has anyone else thought about this?