I think we've gotten all our managers post Fergie wrong.
This analogy may be poor but I see Moyes and Ole as the Pereiras of managers - not good enough/out of their depth and are meant for low tier teams. While Van Gaal and Mourinho are like the Sanchez of Managers - once one of the best but were past it when we got them.
So we should be looking at the Haaland of managers - the top talents and hot prospect hungry for success. Nagelsmann Marco Rose etc fall into this. Or we could look at the De Bruyne of managers - currently the best in the world. Guardiola, Klopp and maybe Conte fall into this category. Or the Firminos of managers - good but not the best currently eg Tuchel, Pochettino, Rodgers etc.
Any of these type of managers would be an improvement on the coaching we've seen post Fergie