Guy Ritchie To Direct "Xerxes"?

Sources have been saying that Warner Bros. have spoken to Guy Ritchie and have asked him to take over from Zach Snyder and direct "Xerxes", which is the upcoming prequel to "300".
It's been reported that Warner want to move ahead with both "The Man Of Steel" and "Xerxes" at the same time, which is impossible for Snyder to do.