Two men in business

When two men in business always agree, one of them is unnecessary.
-- William Wrigley Jr.

This is one of those quotes that get a lot of agreement. But on closer inspection, I think that it implies that the only function of a business man is to generate controversy, and I don't think that's very productive. What if the two partners usually agree, but just are good at different things? Like one has the vision and the drive, and the other one is very good at talking to suppliers and customers and to find good employees.