our rotation is not a guarantee for the entire season, everyone knows hitting catches up to pitching at the season rolls on. in a rotation built around two 40 year old guys, a guy who had a 5 ERA last year and a rookie who's only been decent so far, ANYTHING can happen.
the only thing a good start does for a team is cushion the blow when the inevitable slump happens throughout the season. the division race between the Sox and Yankees swung 6 games in a week, imagine what will happen in the remaining 5 months of the season