I realize this is set in China, and that therefore "samurai" may not be the right word. But before you even think about criticizing my use of it, consider just exactly what sort of movie you're trying to apply a cultural-accuracy argument to.
To reiterate: Nicolas Cage. ENGLISH ACCENT. Looking like THAT.
It's like Hayden Christensen actually went to him and said, "Look, I'm tired of everyone saying I'm a terrible actor like it's a fact. Here are my action figure residuals; make me look good in this."
That'll do, Nic. That'll do.