I don't think you're giving a fair assessment to either side if this trade. Osuna never had one of the highest trade values in the league, and Paulino and Perez are not middle relief prospects. They both have upside as mid-rotation starters, even if there's a lot of risk, especially in Perez's case. Back end bullpen arm or good #4 starter would not even be remotely surprising outcomes for Paulino as early as 2018. That's not a 'middle relief prospect'.