David Carr. Tony Banks. Matt Schaub. Sage Rosenfels. Rex Grossman. Matt Leinart. T.J. Yates. Jake Delhomme. Case Keenum. Ryan Fitzpatrick. Ryan Mallett. These are just some of the mortals that have started as the quarterback for the Houston Texans during the history of the franchise. That’s a pretty mediocre bunch,…