In evaluating a trade, the expectations before the trade don't matter. What matters is the performance after the trade. The expectations before the trade are meaningless except to excuse a trade that turns out poorly.
I'll agree that we won't know whether it is a good trade until the end of the season, but you are jumping to a conclusion that is opposite of the returns thus far. The fact is that you don't know what their production will look like at the end of the year. If the results favor the Red Sox, Cherries gets credit, but right now the results are, at best, inconclusive, so we don't know if it is a good trade. In your opinion, it is a good trade. I am not so certain.