Of 42 senior generals who took part in the US Army's last maneuvers before Pearl Harbor only 11 would command units in combat in World War two. The rest had to be fired or sidetracked as deadwood. Marshall put every candidate through his paces, shifting them into evermore burdensome and pressure packed jobs promoting those who excelled. Those who fail are out at the first sign of faltering. It was like war by General Motors with a risk of corporate strategy more concerned not to lose than to win swiftly.