Maybe its just me, but when evaluating SPs the absolute last cat I consider is Wins
Right on... Wins are totally unpredictable, because they depend on offenses to score runs. Look at Odalis Perez, he had a pretty good season pitching, but did horrible in Wins...even Ishii won more for the Dodgers.
Also, this makes win % one of the most worthless stats for considering how well a pitcher will pitch. The Yankees have arguably the best offense in the major leagues, so yes Mussina will get wins, but you shouldn't look to that as a reason to take him over better pitchers, because better pitching affects more categories.