I can't find the specific article anymore, but it argued that the team trading the superstar away almost always loses. For recent examples just think Sale (yes, the book is not done on Moncada/Kopech), Miggy from the Marlins, etc. The team acquiring the superstar generally wins massively in value. Now, that said, I'm not sure how much it factored in the ability for said team to tank. Even if Moncada and Kopech end up being just decent MLB starters, the White Sox tanked, drafted, saved money, rebuilt, etc. and Moncada/Kopech bolstered what they had so one could argue that. The issue is that it's nearly impossible to find a trade for Trout. You have to find a team that's in the mix to "go for it" that has several top prospects in baseball and feels like trading them. That's generally 1 or 2 teams every year. I'd say it's much more likely to overpay to try to build around the best player in baseball and luck into the playoffs/win it all than it is to find a team willing to offer you close to what the value should be on someone like Trout. 4 controllable years of Trout for instance a few years ago as you suggested they may regret would cost, what...something like Hiura, Burnes, Hader, Yelich, Arcia in theory? Maybe a little less? I don't know, really.