As far as I'm concerned the great thing about sports is that "nice" ideas get proven by success or destroyed by failure. Sports are wonderfully concrete that way.
This is so wildly wrong. There is nothing concrete about sports. Seasonal results in sports, especially hockey, are generated with a ton of luck and randomness, in so many ways. The only thing you can ask of a GM is to do the rational and logical thing in the moment based on the facts, available options, and their available information, so that you have a greater advantage over time.
Though, as mentioned, this was a successful trade in the end. Barrie helped us a lot. As successful as it's maximum potential? No, but most things aren't.