My opinion on Matt Damon- cause why not...
Look, I don't care about this stuff (usually- looking at you "the last airbender"). But I've honestly got to say that I hope they don't actually try to pass Willem Dafoe, Matt Damon, and Pedro Pascal as being Chinese. The director described them as being: "3 soldiers in search of gunpowder who stumble onto the great wall".
So it's possible they aren't actually Chinese. So people gotta calm down a bit.
Matt Damon looks badass in this movie.