players quality

I have a question, why when im play againts team with lower quality than me but my team lose the game 2-0 or more but when im play againts opponetnt have more quality than me, im still lose.
What the most important? Quality or Formation?
formation,tactics....it's the key.....also the using of instructions according to your formation.....you'll see later that having good players and upgrading strategy buildings are nothing if you dont have the best formation
Allright. Thanks a lot
One more question
Whether stamina influential on the game?
it's very important to have good stamina....high ryhtm will quickly make your players tired , maybe after 45minutes ,you ll get pressure during the game...your defenders and goalkeeper wont always be able to stop shoots for example like in the beginning...