If you have one of your scouts go and watch upcoming opponents, his report tells you which formation that team tends to play most often and which they are most vulnerable to. For a long time, I preferred to play a 4-4-1-1 formation which worked well against teams who were vulnerable to 4-4-2 or 4-2-3-1 - which are both formations that the 4-4-1-1 imitates during different transitions of your attacking moves.
My experience at the moment, though - now up to season 2022/23 in my epic trophy-laden Southampton save - suggests that if you play the same formation(s) for several seasons, other teams start to get wise to you. Or, it could be that my attempts to revitalise a squad that was starting to age by bringing in younger players has harmed the Current Ability of my squad - even if the Potential Ability is at an all-time high.
But by-and-large, if you are using a system that is well-suited to the skills and specific attributes - or Preferred Moves - of your players, with a high level of Current Ability amongst your squad, then your team should impose themselves on the opposition so they have to worry about you more than you worry about them.
