Most regular formations can beat any other on a givern day, strengh of the squad, watching matches to get possesion bonus, friends watching, sendings off, injuries, there are so many variables that can make a difference, so play your favourite formation and stick to it. Build your team each season around your formation, tweak it during matches to suit you!, don't try changing your team every timr you come up against a different formation as you will be second guessing yourself all the time.