The important thing to note is that DeBoer has never had a good running game, ever. A thousand yard rusher looks good on paper, but that was a one man show at running back, the #2 rusher was a wide receiver, you can't expect to make it through an SEC schedule with only one running back.
I think what we're seeing is just ingrained into their approach, it even carried over with Grubb to the NFL. However, it is worth noting that in 2019 Grubb was the OC for Fresno St. before DeBoer was there. They managed the 59th rushing offense, which doesn't sound like much but that I think would be a high for either of them without a running QB. It then fell off a cliff the next year (with the same running back), once DeBoer arrived.
So, I think there's a systematic problem here that for some reason a lot of people overlooked. However, they seem to be aware of it and are attempting to address it. You can't win in the SEC with no running game, you can't win if your second best rusher is a receiver (happened multiple years). They just have to adapt and there are some signs they are trying to and are starting to, but learning new things can't be easy.
I would note that you are pointing to years where the Alabama offense went off track though. The only year in which the starting QB won a championship out of those seasons also coincided with a Heisman candidate at running back. Otherwise those are pretty much all years where the running backs tended to be under-utilized and they overly relied on QB play. Specifically that's 7 years with the only championship being a late QB swap (which kind of re-calibrated the offense). I don't see that as a roadmap for success but rather where things started to go wrong.