I have no issues with using an opener, not even a little bit. My problem 100% revolves around using the same opener, against the same hitters, and just generally abusing a couple of relievers while several other decent arms ride the pine.
You cannot expect Aaron Ashby to succeed when he has to face Shohei Ohtani four times in five days. Ohtani (and Freeman) are going to figure him out at some point; it's inevitable.
The Brewers' primary weapon is depth, and Murphy isn't using it, like at all.