Your timeline of Aston Villa's success, in particular, is off. That ownership group had a full 3 years in control before they achieved what they did last season, and saw pretenders like Dean Smith and Steven Gerrard at the helm.
Having said all of that, the stability those ownership groups provided should be what we expect from TFG.
I tend to agree with your sentiment, just not your wording. Stability should be provided from the top in terms of vision and funds to see that vision through.
For far too long, we've relied on the manager and DoF to provide stability, because our owner was a muppet. When we talk about Dyche and the job he's done, that needs to be factored in. That doesn't mean that he should remain the manager, but does deserve more credit than would normally be afforded for managing the situation.
At some level of the business there needs to be stability, it can't be all parties taking extreme risks and not working in concert. Which is what we've been under Moshiri, until he could no longer fund the club and had to rely on Dyche and Thelwell to protect whatever he had left of his investment.