I think for the purposes of narrative they couldn't do that. It is true that the Big 3 and Tejada contributed to the bulk of the A's wins, but what Billy and 'Peter' did should not be discounted. And I don't think the point was that Boston won playing 'Moneyball', but that they won with their money while also employing some of the strategies made popular by Billy and the A's.

I wouldn't consider the strategy 'failing' if every other team started doing it. I'd consider that a success. It would only be a matter of time before the richer teams caught on and caught up, and that's no fault of Billy's. In a world of perfect information the $140 million payroll team will beat the $40 million team almost every time and there's not much you can do about that.

I do agree that the best part of the book was the draft and that wasn't touched on. They briefly mentioned Jeremy Brown but only in a comical sense. Maybe they didn't think having a draft in the middle of the season would derail the buildup to the 20 game streak?