The Cardinals can match up offensively with just about any team in the league but do not have an ace to match the top pitchers of their National League rivals. You can talk all you want about bWar, exit velocity, launch angle, etc., but history shows that teams with strong starting pitching, led by an ace and a solid number two, are just more likely to succeed in the playoffs and win a pennant or World Series.
Anything can happen in a short series or the playoffs, and of course, the Cardinals have a chance to win the pennant and the Series. However, I would like their chances much better if they had an ace at the top of their rotation. If they can’t acquire one at the trade deadline, the most likely outcome for the Cards will be a division title followed by another early exit from the playoffs.