There is not a person alive who thinks Castillo is a better hitter than Reyes. Over the last three years, Castillo has gotten on base at a .358 clip, that’s slightly better than Reyes 0.355. Compare their slugging percentages, where Reyes’ lowest is .421 and Castillo’s highest is .362, and there’s just no contest on who should be getting more plate appearances.
If the Mets want to go to a more OBP conscious leadoff hitter, that’s fine. Hitting Reyes second or third in favor of Carlos Beltran makes sense. Throw David Wright behind those two and you have quite the top of the lineup. Batting Luis Castillo first is taking away plate appearances from your best hitters. Not enough to make a difference, but if Manuel is serious about winning, shouldn’t he be utilizing every asset of the game to its max in order to help his cause?