Garcia is at worst an average defender in RF. His overall numbers are skewed because he has been very bad when asked to play CF. In 4960 career innings in RF, he has a -1.0 UZR/150, and that is only negative because he put up bad numbers at the very start of his career (when he was very young). In recent years he has been firmly above average overall (+6.3 UZR/150 last season). There is no reason for Garcia to ever play CF for us, as he is behind Cain, Yelich, Gamel, and (if there's an extended injury) Taylor in the CF depth chart. Also, in a meaningless sample size (113 innings), Garcia has a career +13.2 UZR/150 in LF. So, no, the numbers do not say he plays mediocre defense at the corners. Domingo Santanta is legitimately terrible and should be a DH, which is weird because I remember when we first trade for him there was still a remote chance that he could play CF. It's like he totally gave up on the defensive side of the game.