This trade fits what the Brewers claimed to want to do all along. Attain as many controllable assets as possible and remain competitive year in and year out. I think some people viewed the Hoskins signing as an all in type of move. I viewed it as fixing weakness while not hurting the future.
I think the run prevention plan this season is to get their starters through four or five innings, rely on their defense and use what looks to be a dominant bullpen more. From what I've read so far, Hall has a great fastball slider combo and a developing change up. In the pen he can rely on his best two pitches more and become the lefty version of Uribe setting up Williams. We also have a lot of relievers who can go multiple innings which helps absorb shorter starts. This bullpen has the possibility to shorten games significantly. The defense looks to be reliably well above average again, somewhat mitigating not having dominant starters who get a lot of strikeouts.
The final piece to the puzzle is what should be an improved offense. A few more runs scored, a lock down bullpen and serviceable starters should be enough to remain competitive as is, and there's still room to add another player or two.