Ralf Rangnick’s Manchester United revolution is still in its infancy, but the fans who streamed away from Old Trafford, having watched the German’s managerial reign begin with a 1-0 win over Crystal Palace, will have done so convinced of what his team is supposed to look like. For Rangnick, 63, the most important statistic from his first game as a manager in more than two-and-a-half years was that United scored…