Silva and Di Maria would be unlikely to be first choice for us (given Nani's recent form)
Silva is a much better player than Nani. He basically does everything Nani does only he's not as wasteful in possession and can pass the ball. Despite Nani's excellent form Silva would have to **** in England big time in order to be edged out of the team by Nani. Not to mention that A) Nani is right footed anyway so Silva could easilly replace Valencia and B) Silva actually plays in midfield for Valencia so he'd be replacing Anderson/Giggs in our 4-5-1/4-3-3 formation.
Di Maria has shown against Everton and Liverpool this season that even playing in a significantly worse side than ours he can compete and while he's a level below Silva he would still be pushing for a place in the team, especially as we can't play Nani and Valencia every game.
so would have all the problems that come with sitting on the bench for long spells and getting the occasional start here and there. In terms of actual performances for United, I seriously doubt they'd outperform Obertan by a significant margin in their first season in english football.
Do you actually even watch football? Seriously? I don't understand where you can come up with such bollocks. In the few games he played for us in the first team Obertan showed that he was reasonably quick, likes to pass the ball to Evra a lot and is capable of the odd very good moment like he showed at Wolfsburg. At the same time he was woeful in a few of his games and Sir Alex has since relegated him for the reserves, because he presumably doesn't think he's currently good enough and I agree with him.
David Silva on the other hand has played 149 games for a top club side in a top league. Has played 33 times for the World's best international side and has won a European Championship and he's rated high enough by Del Bosque and that racist chap before him to start ahead of Fabregas for Spain. You honestly think that a player who warrants a starting place for the Spanish national team wouldn't perform better than a player Sir Alex doesn't even consider good enough to feature for our first team? Muppetry at it's finest. Even the FM muppets have more sense than you.
Di Maria is also way ahead of him with seven Argentina caps (remind me again where on the pecking order Obertan is for France?) and has shown against top Premiership sides that he can do the business.
There's a damn good reason we bought Obertan for £3m from a worse side who didn't even want him and couldn't really understand exactly why we did and Di Maria is being quoted at £20m+. Maybe Obertan will turn out to be a good player but I doubt it personally and he's way below the level of either of those players, especially Silva.