Two people trying to do the same job is a certain sign of poor organization. The bigger the operation, the more complex it becomes. That's why the alert manager makes it clear to employees exactly who is responsible for what. There is a tendency to overuse a capable worker. A wise manager knows that if you give even the best subordinate responsibility for too many jobs and too many details, efficiency is bound to suffer.
Good managers take nothing for granted.
Nor do they assume that employees understand their assignments simply because they ask no questions. The effective manager periodically reviews the work of all employees to make sure that employee and manager have the same understanding of each job. Too many chiefs are worse than too few Indians. The employee who is not certain to whom he reports is never sure of what is expected of him. The manager who countermands orders, or issues new assignments without informing employees, destroys efficiency.