In 2007, the Cowboys had the best record in the NFC by starting Julius Jones, and having Marion Barber come off the bench in the 2nd and 4th quarters. A whole lot of people said that Barber was a better RB than Jones, and that Barber should start instead. Barber even made the Pro Bowl that year instead of Jones.
In a brain dead move, instead of sticking with the winning formula that worked all year, the Cowboys under Wade Phillips and Jason Garrett decided to start Barber in the playoffs. He had almost 100 yards in the first half against the Giants, and then disappeared in the 2nd half. The Cowboys, after beating the Giants twice in the regular season, lost in the playoffs. The Giants went on to win the Super Bowl that season.
This year, instead of sticking with a winning formula of using BOTH Zeke and Pollard, some fans think Pollard should be the full-time starter. They want to change out the recipe of using both players to wear down the opposing defenses. There may be some merit to cutting Zeke next offseason, and signing Pollard to a new contract before he hits the free agent market in March. But for now, Cowboys fans need to calm down. The Combination of Zeke and Pollard has led to winning more often than losing. McCarthy says they look at Zeke and Pollard as 1A and 1B. They are Both #1 RB's, and the Cowboys are fortunate to have such a strong team of RB's to use this year.
My opinion – Enjoy both RB's this year, and let's wait until March to make a decision about next year. Pollard and Zeke splitting 25-35 carries a game is working. Don't mess with success.