I'd rather face Reed Johnson with a chance to get out of the inning unscathed than to pitch to Simmons to possibly get out of the inning unscathed.
??????
You just offered a scenario in which both sides of the equation are equal.
At least my theory allows the Nats to face Medlen to lead off an inning.
Besides, you asked why and I answered your question. You wouldn't do what Davey did. Bully for you. He's a baseball manager and you aren't.