The NFL offices employ about 800 people. No doubt, as with any company, they have many levels of management that run the business. And no doubt Goodell acts as counsel to the owner group on the big issues.
But there's no way around the obvious fact that Goodell is a well paid figurehead. When real decisions are to be made (expansion/team movement, CBA, TV contracts) the owners make all decisions. No one even expects them to speak to the public. The make Goodell do this.