Moreno is most certainly a top notch prospect, but it's not like Kirk and Jansen are anything to sneeze at. The Jays are well covered at C, and have more in the pipeline. Moreno currently has some questions about his game calling and power. Not big ones, but ones nonetheless.
The question boils down to this. Who provides more value today to a win now team? Moreno may have even started in Buffalo.....or at the very least, played infrequently, and all over the diamond.
You give to get. And according to baseball trade values, the D-backs were the ones who overpaid.