I feel like you're underrating Greinke a bit here. This is a good get for the D-Backs for sure, but Greinke is still an excellent pitcher and they're acquiring an incredible amount of risk. That's a pitcher currently recovering from Tommy John, a DH headed to the NL (although Beer absolutely rakes), another pitcher with great stuff and bad command, and a depth infielder who to his credit has hit at every level. Greinke could out-WAR this entire group over the next 3-4 years, and the Astros will have him for 2.5 seasons + the postseason.