Copying your opponents style to beat him will never work......It will a foolishness to do this...

He will be playing his best players and would have build up him players according to it...While you in order to play his formation will have to make a lot of changes and probably will have to rest your best players...

Your opponent would have been playing his formation for quite some time and he would be experienced in it...

Just play your own style and let the opponent defeat you...Its the best way because you are playing your best 11......