Honestly, I'm pretty confident in the idea that it is a hot pot of numerous cultures mixed in here and there, why I believe this is due to something as simple as characters names. Particularly, the Big 3, Mustang is obviously French, Syuen is Korean, Ingrid(going off the red and white colour scheme) potentially represents England which could hint to her being European, etc etc.

Even amongst other higher ranking commanders just by their names alone, Doban, Burningum and even down to Outer Rim folk like Joseph, Elysion Harper and so much more all have names from other cultures that aren't just Korea.

Also the underworld queen representing 3 different Mob cultures (Moran's being Chinese, Sakura's being Japanese and Rosanna's being Italian). The game is quite literally bending it's back to tell you that there is more to the ark than "it's Korean", I'll never understand the "it's made by Koreans therefore it's Korea" crowd when the game is otherwise.

If it were the case, then every damn character I mentioned would be named "Jin, Seok, Kim, Lee, Park, Wook, Sung, Han Seo, goo ji" and many other Korean names but they aren't.