I think people are reading too much into Red Zone Offense as a statistical ranking here. As the NCAA records it, it is simply the percentage of times a team scores after entering the RZ. FGs count the same as TDs. So missed FGs and red zone turnovers are the biggest issues. Miss a few chip shot FGs and fumble a few away inside the 20 (ala Book/Clemson Rd 1), and your percentage tanks. This particular stat is mercurial by nature, which is why ND's ranking varies so greatly year-to-year. It is also why Eastern Michigan was ranked #1 last year in "Red Zone Offense" while Ohio State was ranked #100.