Riddle me this: how is leading off with Tyler Colvin any different from leading off with Alfonso Soriano?
Hint: It's not.
The one-spot should be given to Castro or Byrd. (Marlon is 2nd on the team with a .378 OBP; Soto leads the team in OBP with a .407, but I don't suppose you want to see his slow ass at the top of the order. Castro is 3rd with a .350 OBP so far this season.)