Bettcher is a curious case, second year in a row the defense starts the season out of sorts. Last year it seemed to be communication in the secondary, this year it was the ridiculous amount of zone, probably to cover how bad Bethel was and how tentative HB was playing. Also, nothing creative in play design for creating pressure, soft defense and lack of adaptation.
Swap out to T Williams, HB starts playing faster and the addition of Buddha...means we go back to man coverage, line stunts and some creativity starts to show on pressures, etc.
So if I blame him for our early failures, I have to credit him for the late success. That would suggest the bigger issue is player evaluation in the offseason and training camp. That sounds like a BASK problem instead of Bettcher.