With Thomas getting some play in CF, I'm not sure Call is needed for that. His defense is an upgrade on every outfielder not named Robles, and he can provide a bit of pinch running, which is one of Chavis's uses. Neither is showing much pop vs. in the past. Vargas is an adequate backup at 2d/SS/3d. Only thing in Chavis's favor is, in a pinch, when a 2d backup is needed, the infield is more exposed than the outfield (that is, I'm more comfortable with Chavis or Meneses in the outfield than I am with Call or Meneses trying to play 2d/SS/3d).
I think the Dickerson/ Garrett platoon in left is working, and frankly think that there should be times when Smith sits, Meneses or Adams is at 1st, and Garrett DHs. Dickerson is just a better hitter than