Yeah, this is a good post. AA has seemingly improved a lot from the days of ignoring defense, buying pitchers based on ERA, investing heavily in relievers, and rostering awful players because of character. He's not a below-average GM.
But I don't think he's bright enough that people should worry if he leaves. There are others who can do as good a job, or better, and with Shapiro at the helm the team has one of the Presidents most likely to fill the GM chair with a quality guy.