Nani and Young as left wingers, Valencia as right winger with Kagawa as AM and a bunch of old very experienced midfielders is not that bad to be honest. Fletcher's death is what weakened their midfield the most ... and the defense is just horrible (along with the goalie).
United are leading because of their character aka Ferguson in the EPL. With or without RVP they'd be up there (just like last year). They'll have a world class squad with a couple of additions.