Man Utd play a different brand of football to us. It's more direct and the players are more disciplined with their positions.
Also, Pires and Ljungberg especially were effective because they had Bergkamp and Henry up front. Two very unorthodox forwards. Henry would drift to the left and confuse the left fullback giving space to Cole and Pires. Bergkamp would drop very deep which opened up space for Freddie run in on the space behind. Giroud and Theo are very different players and get goals when the ball Is played into space in front of them. We'd have to wait and see how it would work but I wouldn't compare this team to past Wenger teams and think it could operate in a similar fashion. I'd go as far as saying the reason the Invincible team worked was because it was completely organic. The movement and positioning just formed naturally because it’s how they wanted to play.
We'd have to see how things pan out but I don't think Ramsey has the quality to hold down the middle on his own. He'd be seeing the ball much more often and would be surrounded by more players. The centre is like the hub. He'd have to pick out passes quicker, more accurately and constantly be on the move. A bad touch or dwelling too long on the ball means he'd get clamped down on.