I
agree with Dickay
I don't think the WBC needs fixed. Improved-sure-everything can always be improved.
Though, this is a tough one. The way they are doing it now, is probably the best way.
If the US WANTS to win in the WBC, then they need to find players that will commit to the WBC and get ready to play in the WBC instead of using the WBC to get ready for the major league season.
Since the major league season is what pays them millions of dollars, there might not be a lot of players who want to do that.