What do proverbs tell us?

'Too many cooks spoil the broth', 'Many hands make light work', 'Red sky at night, shepherd's delight, red sky at morning shepherd's warning' are all proverbs. But one thing that puzzles me is that the first two contradict themselves, 'Too many cooks....' means that too many people doing the wrong thing they will end up ruining it, but 'Many hands....' means that the more people doing a job the better, and the quicker it will get done!!