I think the part you're missing is that Stearns likely thought the Brewers could do a lot better than Aguilar for his cost. He was wrong (kinda). I mean Gyorko is far better than Aguilar, so it the Brewers don't deal Aguilar, they don't have Gyorko, and are therefore worse. So Stearns wins another trade. Not sure why keeping Aguilar would have prevented us from signing Gyorko. Signing Smoak didn't prevent us from signing Gyorko, and Gyorko is far more versatile than Smoak. Gyorko wasn't signed to be the primary 1B this year. It just worked out that way from lack of other options.