I get what you're saying because the draft is mostly an exercise in luck - misjudged ability/ceiling, injury, system, etc. At the end of the day, though, the top personnel person(s) have to make a decision. And I don't think you just assume, in the example above, that the three WRs projected to be top 10 picks are all the same., and any of the three fill the need the same way. If you believe one to be/not to be a standout, you may consider making the move. I'm not suggesting "trade-ups" are the way to go. As mentioned by someone else, ill-advised trade-ups are magnified. But there are plenty of instances where trade-ups were great moves.