Sorry, you mean I (a manager of my club) can not change the formation of my team during the match? So, if i started with 4-1-2-1-2, then I have to finish with the same??????
I think, even it is illegal to change the formation, so I have the one player with not his position, so, ok, let's imagine I have no more this player this way - I have only the 10 players. Even in this case it wouldn't make me 20%.