The perception that only elite schools produce elite leaders needs to die. The No. 1 company in last year’s Fortune 500 was Walmart Inc., with $500 billion in revenue. That would make its chief executive, Douglas McMillon, a pretty important and powerful executive, don’t you think? Can you guess where he went to college? The University of Arkansas. He has an MBA, too. From the University of Tulsa. Second on the list was Exxon Mobil Corp. Its CEO, Darren Woods, went to Texas A&M. Third was Berkshire Hathaway Inc., run by the man many consider the greatest investor who ever...