If they wanted to be tricky about it they could claim that it was based on a true story. A sly play on words.
Based on a true story. Not in the sense that the story is of a true occurrence, but that the movie was based on nothing but a story. Or to put it another way, Truly based on a story. Hope that made sense. Just me being facetious.
I liked the movie, but no way is a horse straight off the grasslands in America going to kick the butts of desert born Arabs. But I am a little biased. :P