FWIW I don't think the
Moyes model works for many managers. Allowing them to control recruitment etc is not always the best idea. For instance Jurgen Klopp didn't want Salah - his preference was Julian Brandt, as he had admitted, but Liverpool's scouting and data people convinced him that Salah was the outstanding candidate for the role they wanted to fill. The "eye test" is not always the most reliable one, but it's the one which most managers rely on.
Finding a manager who has the time and ability to coach the first team to a high standard and control recruitment is a huge ask. There aren't many about. It's why the DOF model is there. A DOF controls a lot more than recruitment usually - there is a recruitment department with a head and they do their thing, along with medical, loans, etc - the DOF just oversees it all. It doesn't usually mean that the DOF is solely responsible for recruitment.
The structure we decide upon will influence greatly whether a DOF is required, but, importantly, the role of a DOF differs from model to model so it's pretty pointless us all offering an opion on whether the role is required until we know what the structure will look like