Because you change alot of players it takes a few games for them all to settle in, some of them you may need to swap positions, i.e, swapping your DC OR MCs or ST round, depending on what positions you have changed, take a closer look at the players stats and check what foot they prefer and adjust position to suit!, you also have to take into account that you may have bought some slow trainers if they are not hot prospects, have you got the condition up to full?, I like you change alot of players every season, well a whole team in fact, my best team becomes my 2nd team and my first team is a completley new squad!, dont you do this as I have plenty of tokens so I can afford it but you do what works best for you!, as I was saying my first team took a few games to settle in, adjusting orders, arrows etc to see what works best!, the only thing not to do is keep changing your formation as you will be doing it forever as there are to many variables in this game from game to game to get it perfect everytime!.