I kinda change my formation form game to game depending on the opponent. Once in a champ league match I lost my first match 2-0 with a formation I usually use. Second match I decided to attack so I placed 3 st 3dc and 4 midfielders (3-4-3 formation). One of my midfielders was red carded on minute 20 so I had to place hard attacking with full pitch pressing and offside trap. So after that I scored 3 goals and won the match after thenThat my be a coincidence but after that match I had the cup finals match vs a full 5 stars team average 27. I had an average of 24. So I used 3-4-3 and I had 55% possession and won 2-0
That was a great win and I still use that formation after that day.