#3 - Dylan Carlson
I don't think many Cardinals fans would have a huge problem with them giving up Dylan Carlson to acquire a good starting pitcher with years of control. And therein lies the problem in ranking Carlson higher as a trade piece.
I like Carlson, and I go back and forth on him as a player. I still believe it's going to "click" for him at some point and he'll be a .280-.295 hitter with 15-20 HR power, doubles galore, and a good on-base percentage. But unless another team sees that in him and is willing to trade for him with the value of a guy who is that, I don't think he nets the Cardinals the kind of pitcher they need as the centerpiece of a deal.
In a really aggressive move, Carlson could be the second-best asset they give up, or he could be the best asset in a trade for a low-ceiling controllable starter, but I don't see how he gets them in the conversation for some of the best young arms around.
Carlson plays a great corner outfield defense and is a very capable center fielder as well. Those guys have value. The problem is, they don't have the value of a starting pitcher with control. It's easier to replace Dylan Carlson than it is to replace an impact starting pitcher with longevity.
In all honesty, I think Carlson will have more value staying with the Cardinals than being the headliner in a trade. I would rather St. Louis part with an asset that is going to hurt a little bit more to get a very good starting pitcher than give away Carlson for an okay option.