As a college player, Frelick probably is the BPA, or maybe Kumar or Leiter, over a HS...what you're saying is you don't think he's the best future talent available. BPA isn't as cut and dried as you're trying to make it out to be...and that's especially true in the MLB draft. You're trying to balance ceiling, with likelihood to reach it, with floor. But the variety of outcomes is exceedingly high, even at the top of the draft.
You make it sound as if there is a very clear pecking order, with large gaps differentiating the players, and that's just not the reality.
I agree though that not drafting someone bc you already have someone at that position is silly.