Cuddyer, Kubel and Restovich were all top 30 prospects.
I won't disagree that the Twins didn't know how to build a championship team back then, but that's mostly because they traded the less valuable guys, like Kielty, Buchanon and and Lawton (who'd be the Polanco comp here) instead of trading the more revered prospects for pitching. We were begging for them to trade for the top arms like Halliday, Sabathia and Lee but they never did. Losing Cuddyer would have hurt, but if this team uses one of those guys to get Curt Schilling in 2004 instead of the Red Sox, maybe we'd have had a World Series trophy.
Also, keeping them all not only meant wasting the equity, but it was pretty crappy to the players too. Of those three names listed above, one sticks out for being a bust, but that possibly had nothing to do with him as a player. In the very spotty opportunities he got with the Twins, Michael Restovich had a MLB OPS of .807. The Twins didn't set him free until he was 26 and out of options. He's now a middle-age man who certainly looks back and wonders what could have been had he been given an actual chance.