Vierling is batting .263/,302/.422 with the bases empty and .229/.279/.458 with RISP in limited PA. So, he does not seem to have excess clutchiness. I think clutchiness exists in certain players, but that it's so minor that you can't rely on it on a regular basis. You can't plan around it.
Match-ups do matter in the playoffs and throughout the season and I think managers such as Hinch know how to take advantage of them, but you can't know who you are going to face in the World Series. You can't build for a championship. You can only build a talented team that makes the playoffs multiple times and hope that things go right in post-season.