By Tom Victor Sir Jim Ratcliffe has already secured the CEO and sporting director changes he wanted at Manchester United, and now it’s time for him to decide if he already has the right manager at the helm. Ratcliffe’s arrival at Old Trafford was announced by the club on Christmas Eve and made official in February. While the summer transfer window will be the first chance to get a feel for the billionaire’s plans for the playing squad, he’s already started to change the things in his power. The 71-year-old has been given control of footballing affairs after taking a 25 percent stake at a cost …