Atlanta cleans up in Gattis trade

In dealing a trio of prospects for Evan Gattis, I really don't understand what the Astros are doing. The prospect depth they have in their system could allow them to acquire a player of a much higher caliber than Gattis, preferably a younger one as well, someone who's going to contribute to the next good Astros team in a few years. Atlanta, meanwhile, has gone from a bottom-five system in baseball to likely a top-10 system, overhauling its major league roster while adding a broad mix of near- and long-term talent to its farm, in this case trading a player somewhere near the apex of his value for