No, I'm not. The original quote was that high end SS prospects have as much trade value as high end pitching prospects. If tey can rake like Tulowitzki or Profar is now, that may be true. However, Zack Cozart never had a ton of trade value, just like DiDi Gregorius now, because he couldn't hit enough to play anywhere else. In this day in age, if a prospect doesn't have the potential to OPS .750 or .800 in the big leagues, he won't have a ton of trade value. The one exception to that may be catcher.
I'll be surprised if Marrero hits better than Cozart did in the minors, and Cozart never carried premium trade value.