I agree with all of that. The Brewers have played over their heads a bit, as evidenced by their run diff. But those wins are now banked and if Milwaukee's health continues to hold, they're a better team right now than they were during those banked wins so their previous mediocrity may not represent who they are today.
But the SoS favors the Cubs, which should make this a tight race until the end unless one of the two dominates in head-to-head matchups.