I think the 1/72 scale stuff next to FOW buildings looks fine - but I LIKE my buildings to be a little small in comparison to figures and vehicles, especially on playing areas as small as those used in AA. I think the 1/72 scale stuff looks a little too big next to 15mm infantry, though.
I also have lots of thoughts on the economy, the proper management of society, the best beer, etc. . . . so don't let what I say discourage you from using whatever YOU think works to play the game. We don't sell figures, so we have no interest in dictating what the "right" toys to play the game are.