The easiest way to identify a Chinese seller is by the name (it will be in all caps) or the short description will contain bullet points enclosed in square brackets. E.g.:
* [easy to use]: blah blah blah
The reason for this is most Chinese sellers use a CRM to manage their Amazon listings. It helps them go through the process of creating their brand and capitalizes the name. The description also has a predictable format. I have no idea what else they offer, but they clearly offer a way to absolutely dominate the search listings.
My advice to non-Chinese sellers would be to allow users to find your product in other ways. E.g. I often search for products made in America or ones at least designed in America so I can have someone to blame if something goes wrong. Make sure your product shows up if googling "Product X made in Y." If your product is made in China, then just give up because you're just a middleman. There is no winning strategy when the producer wants to cut you out.