In 2018 Warwick University had it at 31k managers in NHS England with a third of them also either doctors or nurses with clinical responsibilities. Government reported 116k NHS England doctors and 285k nurses in 2019 so I'm not sure what you misunderstood to reach your conclusions - everything, possibly.
Whatever else it is, the NHS is a massive watering hole and staff at all levels do really well but they have to play by the rules, that's where Stannard went wrong.