It's very close, but playing a 2 in left and right is slightly better.
With 2s, you have fewer doubles: DO2, SI2, SI2 x2 versus DO3, DO2, DO2, SI2, SI2, SI2 and none for hit chances off of the X chart. Also, none of your doubles will advance runners 3 bases. (The number of chances for giving up any kind of hit is equal.)
It's trivial, but you also get one less chance for a fly out runners advance 1 base by playing 2s instead of 3 and 1.
https://img.photobucket.com/albums/v496 ... errors.jpg