1
general::
Too many persons involved in managing an activity can ruin it, as in Without a conductor, every player had an idea for how the music should go? too many cooks spoil the broth. This expression alludes to each of many cooks adding something to a soup, which finally tastes awful. It was already considered a proverb in 1575 (by George Gascoigne in The Life of P. Care).
American Heritage Idioms
2
general::
Phrase(s): Too many cooks spoil the broth.
Go to Too many cooks spoil the stew. and Too many cooks spoil the broth.
McGrawhill's American Idioms And Phrasal Verbs