Offensively, Matt Carpenter would be one of the single best second basemen in history, let alone St. Louis Cardinals history. No, for real. I’m not joking. Stop laughing. In all seriousness, Marp shakes out on top.
In his career, Carp has an OPS+ of 130 (OPS+ is a league-average adjusted statistic, where 100 is exactly average).
Robinson Cano is at 127, Dustin Pedroia at 114, Roberto Alomar at 116, Craig Biggio at 112, and Jose Altuve at 126. Carpenter has been better at the plate than every single one of those players for his career.