I think a major factor is that while our core hitters are leaving their prime years, the Brewers core hitters are only just approaching theirs. Adding Gallardo (assuming he comes back fine in mid april), Parra, and Villanueva to the rotation for a full year in place of Vargas and Capuano should be a big improvement from within. They are also adding about 2 months of a very good hitter by having Braun for a full year. They also signed a decent centerfielder, which allows them to improve the defense a bit, by moving a natural infielder back to the infield and getting Braun in a spot where his lack of defensive prowess will hurt them the least. I still think the Cubs take the division, but I think it will be a very heated competition.