And trading for young SPs is risky - imagine if the Jays had traded d'Arnaud for Pineda last off-season. That might have been a historically bad trade.
Drew Hutchison was getting better, it's possible he "figured it out", when he went on the D.L. Drew was a good draft pick and should be a good pitcher (potential). Michael Pineda was already good when he when on the D.L. (established) Trading your #1 prospect for a #1, a #2 or a #3 Starter (like Shaun Marcum) is a good deal. (Precedent: Milwaukee's Brett Lawrie for Toronto's Shaun Marcum). New York won that deal.