Well Haren was easily for the last decade, but 2012 gives you some question marks on how he will perform in 2013. If each is going to perform like they did up until 2011, then Haren destroys Buehrle. But it's an if depending on Haren's back.
Why is Buehrle being talked about as a number 3? He's likely the "fifth" starter next year. The Jays can throw out 3 potential number ones in Morrow,Dickey and Johnson. Morrow especially, I don't think people realize how good he can be. I smell cy young votes next year. Not to mention Romero who could easily return to form. That's not wishful thinking either, Ricky is a legit pitcher and more importantly, despite his struggles last year, it wasn't because he lost any velocity. Haren continues losing velocity, which is a scary sign. I'd like him in my rotation but I wouldn't bank on him.