A lot of successful managers are like Alex Neil, they come out of nowhere with no promotion form but plenty of enthusiasm and a high workrate, and the team just clicks. Other times it doesn't work, as David Weir showed. Managers with plenty of promotions on their CV's don't always come good, as we saw with Wilson and Micky Adams.
Numerous well-known managers are available with decent records, but they are overlooked as they are older and didn't succeed at their most recent club. It seems like the trend today is to employ younger managers in their 30's and 40's, not those in their 50's and 60's. The managers of Man City and Arsenal are a couple of notable exceptions.
There are plenty of candidates that fit the bill, young and old, but no guarantee of success with any of them.