The obvious example is Steve Jobs. He turned around two floundering companies - Apple and Pixar - into immensely valuable companies, without changing the employees. You might argue that one was luck, but two? One right after the other? and the two were totally different businesses? You've got a lot of 'splaining to do about that.
See "The Making of Steve Jobs".
In fact, read any history book that focuses on one person or business, and find one that became a billionaire by blundering about.
As for them not being self-made, why didn't their makers, if they were so smart and endowed with resources, become billionaires? Are they so generous?
Haven't read it, but I've heard there is a section of Creativity Inc where Ed Catmull talks about working with Steve and how they operated.
Finally, there's a site that occasionally surfaces here which had stories from the original Mac team. Folklore.org I think? That was a more raw period with more of a mix of immaturity in there.
But all of those have a variety of firsthand accounts.