I don't think it's possible to judge a manager by in-game moves. Billy Martin? Yes. He over-thought everything...tried to play chess-game with his lefty-righty match-ups and even a good left-handed hitter will fail two times out of three. The 1978 season is a good example of Martin's style compared to Bob Lemon's "pick the best players and let them play" style.
Only judge by the results of a long stretch of games. This Nats team has not cracked even though Fister, Ramos, Zimmerman, and Harper have been out for a long time, and Span missed a week after the collision. No telling if, or how long, the collision affected Span. They're still winning, and just took two of three from the Dodgers.
So far, Williams looks pretty good. (If he gets into a bar-fight with Strasburg or Zimmermann I'll change my mind quickly!)