My only concern is which one to build around and which one to discard. One player is 28 while the other is 38; seems like a pretty easy decision to me.
FWIW, those defensive run values are better than I've seen, but I'm still not going to buy the fact that a left fielder can be as much as 15 runs above or below the average. Perhaps a catcher or shortstop, but not a left fielder. The vast majority of defensive run value belongs to the guys on the mound, and rest of the small pie piece is divided among nine gloves with the left field glove being one of the two or three least important. There simply isn't enough runs to go around.