Jo Adell was the #1 prospect in baseball at one point man. Yes, there were some question marks, but you can't pretend like everyone knew he'd be a bum. Most/all prospects have something they are still developing. It's very difficult to know which ones will figure it out and which won't. Great GM's f*** up that evaluation all the time because there's always a probability of failure that is often outside of their control. It's just like a great poker player. They know the odds inside and out, yet they still lose quite often. In your theoretical scenario, you have to factor in the likelihood that one (or both) of the stud prospects you trade Vlad for could bust - with little to nothing you can do about it.