The characters weren't original; the way they were portrayed was. You think that's the only American corporal in a film, or even a story, that claims to have Indian blood and to fight like one? And that's certainly not the only story about super Jews beating the crap out of people who beat them down. There are entire comic series about those kinds of guys.
I said they were "fresh and interesting", not new. It's like Thor (2011). I actually really enjoyed that movie. It's not a new idea, or a new story. In fact, the story has been done probably more times than not. It's damn near every James Bond story. However, they handled the characters in such a way that it felt compelling to watch. They didn't go overboard with the "fish out of water" part when Thor gets to Earth. They showed a few differences, but Thor adapted quickly. Why? Because he's the
motherfucking God of Thunder, not an idiot.
I thought Tarantino would be a good place to cite where you can find something new and fun in a familiar story, because he uses the same stories he saw as a kid. But, he's smart enough as a writer/director/filmmaker to add elements to keep the story intriguing and, well, fresh. I don't mind the use of the familiar elements, but the fact that a lot of these movies are reboots and flat out remakes is frustrating. We may not have all seen Wicked, but we all probably know what it is. So why does this movie need to be made? Oh yeah, take two famous actors (Franco/Kunis) and a familiar name and it'll sell.