When Walmart last week announced that David Guggina, its U.S. e-commerce chief executive, would become CEO of its nearly $500 billion U.S. division, one thing stood out in his résumé: Unlike his predecessors, Guggina has no experience running stores and has never held a merchandising role, at Walmart or elsewhere. These are two classic job requirements in retail. Incoming Walmart CEO John Furner, for example, who has run U.S. operations since 2019, began his Walmart career as an hourly associate in 1993, an ...