See this is what I meant by fish and water. The focus on the wilderness is a big part of the American influence.It depends on the writer and game designer in question. If they are a Roman history buff, and not into westerns, frontiers like the Roman Danube will have more of an influence. If they are into wuxia, southern China is probably more of an influence. If they are into westerns, the western frontier. But I also don't think americans equate wilderness and frontier. Like I said, we have large state forests and a lot of us spent time camping in the woods growing up
And yes. A game set in China will have Chinese influences, but unless the GM and players are very very deeply steeped in Chinese culture and language and history, if played by Americans it's going to be very American.