You were so lacking pace for much of the game so United were able to play the taller defenders who snuffed Giroud out. And Bendtner is so second rate right now.
But with that clever midfield and Walcott to run onto passes you'd have won by 2 or 3 IMHO. Walcott and Rooney are right now the only English players who could get in top teams like Spain or Germany.