Manchester United played with 4-3-1-2 line up.
RB Leipzig played with 3-5-2 line up.
Leipzig couldn’t make game from wings or centre because they hadn’t any numerical advantage in the side.
In the centre midfield, they remained 4 vs 3 and they couldn’t make game.
Stoppers couldn’t support attack well because Manchester United could cover them with 2 centre forwards greatly and if 1 stopper was free, Van De Beek closed to the forward line and when he closed, they could cover Leipzig’s stoppers with 3 vs 3.
In the wings, both teams had 1 player so Leipzig couldn’t use wings either.
Actually Poulsen and Forsberg remained 2 vs 2 in the centre forward line against Maguire and Lindelöf. When Nkunku or Olmo closed to the forward line, they could have numerical advantage in the centre forward line with 2 vs 3 but they couldn’t use this advantage. Because they couldn’t make game from defense.
But Manchester United had numerical advantage in the left wing. When they made game, Fred came to Matic’s side and Pogba supported attacks from the left half-space. And when he came, they had numerical advantage in the left wing with 2 vs 1.
And in the first goal, they could score with this advantage.
Pogba has the ball in the left half-space and when he has, he can be free and Henrichs is close to Shaw. So Pogba can dribble easily and pass to Greenwood. Then Greenwood scores goal.
In the 25th minute, Nagelsmann changed the line up with 4-4-2. Nkunku and Angelino were the wingers.
Now in the centre midfield, Manchester United had numerical advantage with 4 vs 2 but in the wings Leipzig remained 1 vs 2 against the opponent’s full backs.
In the left wing, they couldn’t attack effectively. Normally Angelino is not a winger and Halstenberg didn’t support attacks much. He usually was the 3rd stopper.
They tried to attack from the right wing. Henrichs could support attacks comfortably because there were 3 defenders in his behind.
But Leipzig couldn’t be effective in the right wing. Because this time Pogba closed to the left wing and they could defend the left wing with 2 vs 2.
When the score was 1-0, Manchester United defense line went back more. And this time Forsberg had more space and he could take the ball more comfortably. But still Manchester United had 3 centre midfielders in the centre midfield because Van De Beek closed to the midfield and helped to cover centre midfield. So Leipzig couldn’t have numerical advantage and remained 3 vs 3 in the midfield.
So Leipzig couldn’t create goal chances and Manchester United could score goals with counter attacks easily with the forward players who attended the game later. Leipzig’s defenders were tired and they couldn’t challenge against them.