When they ask me what formation you use ? i always say " i have no formation ", i always adapt. When i started the game my aim was to find a " Universal " formation that can be good against all other formations, but at the end i realise that there is no perfect formation. Of course you can find a formation that is good vs many but every formation have pros and cons. Is up to the manager to find a suitable formation for every match that have more pros than cons. I believe that this is one of the reasons why that some managers get trolled in some matches even if they are stronger, 1 day you can you meet a weaker team have a formation that is " effective" against yours and this is where a tactical change/ formation change can save your day.