Chpettit19, this isn't directed uniquely to you, but I'm going to respond to this one because I also consider myself "annoyingly neutral" on managers. And despite what I'm going to say next, I'm annoyingly neutral on this decision.
For his career, Farmer has hit righties better than Wallner has hit lefties. For this season, Farmer has hit righties worse than Wallner has hit lefties. But overall, Farmer hitting against a righty or Wallner hitting against a lefty are both bad options to choose from.
But there's another variable. Somebody throws the ball. And in this case, there's a pretty big difference between Marmol's resulting options.
Going into today, for the year, Romero has a 1.5 bWAR and a 2.45 ERA that translates into a 173 ERA+. For the year, Armstrong has a -0.4 bWAR and a 5.02 ERA that translates to an 81 ERA+.
So it's not as simple as choosing Wallner against a lefty vs. Farmer against a righty. It's also choosing Wallner against a lights-out lefty vs. Farmer against a raunchy righty.
I join others in saying that a downside to choosing the Farmer option is what it did to the defense, and that definitely ended up biting us.
But there were also likely eleventy-seven other factors that went into the decision, and I'm not smart enough to claim that I know them.
As I said, I'm annoying neutral on managers, primarily because of the previous paragraph. I try not to use the words "always" and "never" because there's a lot of gray in life. But here's a sentence in which I'll use both. There is ALWAYS more information feeding into a manager's decision than we are aware of, and we will NEVER have access to all that information.