I can't get worked up about the Phillies failing to sign Yamamoto. As great as he has been in Japan, there is no track record of that translating to a superstar MLB career, or leading teams to championships.
There are only three Japanese players who have average 3 WAR in MLB: Ohtani, Ichiro, and Kodai Senga's first year with the Mets. None of them have been to the World Series. I could find only four Japanese players who had over 2.5 WAR in a seasons where their team won a championship: Matsuzaka (4.1) and Okajima (2.9) for the 2007 Red Sox, 38-year-old Koji Uehara (3.5) for the 2013 Sox, and Hideki Matsui (2.7) for the accursed 2009 Yankees.
This isn't to say that Yamamoto was a bad signing for the Dodgers, but it doesn't come close to guaranteeing them anything. Nor would the Phillies signing him have done so.