Snow White as a warrior on horseback? Really? I'm no expert here, but allow me to explain.
Snow White was something about a princess who survived several assassination attempts, and seven midgets with a small mining concern.
Joan of Arc was a schizophrenic cross-dresser who fought for France in the Hundred Years War.
While Kristen Stewart, the fairest tomboy of them all, would be perfect for either role. They are not the same story.
I do not want James Bond with zombies, Westerns with space aliens, or Terminator, The Musical!
Write something original, and stop mixing up stuff at random like some monkey bartender. Mash-ups are for fourteen-year-olds posting on YouTube. You are grown-ups who make movies for a living. Enough already.
Some Hollywood dipshit probably tried pitching Snow White and the Seven Hobbits and they wound up keeping it.