too many cooks spoil the broth

too many cooks spoil the broth или stew

Предприятие скорее всего провалится если им будет руководить много начальников. — поговорка.

When several people acted all at once in trying to reshape the company's investment policy, Tom spoke up and said, "Let me do this by myself! Don't you know that too many cooks spoil the broth?"