I do that also, and not only that, but I put a voice and accent with the character as well. Trejo definitely looks the part. His face already looks like he's got scars, just like Rainbird. But, like OldDarth said, it really needs to be an actual native American. Trejo almost has the voice down as well, and he could definitely learn the accent, but it's hard to picture him as anything but Hispanic.