Why German standardization required design discipline, not just standards

What if Germany adopted genuine industrial standardization before or early in the Second World War?

Production would become much more efficient, but the essential reform was freezing designs long enough to build interchangeable equipment instead of introducing small changes throughout a nominal production run.

Germany could announce a run of one design while changing components every few hundred vehicles or aircraft, leaving machines with the same name but poor parts interchangeability. The United States sometimes completed B-24s to one factory standard and sent them to separate modification centers rather than disrupting the main line. Britain similarly introduced Spitfire marks by factory and demanded that a change justify its production cost. The German modular submarine program supplies the warning at sea: sections nominally built to one standard could still fail to match when yards tried to assemble them.