When manufacture is outsourced to China it creates an entire secondary market of genuine fakes. The same factories that produce the real thing in the quantities ordered will also produce some extras to sell on the side.
They're identical. Side-by-side you couldn't tell the difference but it's the lack of a true connection to the brand that makes them technically fake.
With limited run Nikes being hoovered up by collectors and resold at a premium, the genuine fakes are a way to get the same item and actually wear them without the stupid markup.
These Tom Sachs Mars Yard 2.0 Nikes are something I want, and while £175 is far below any kind of official pricing, it's still way beyond what I can spend.