Thx for your input.
But its a fact that a lot of new players in your starting 11 effects the scoring chances. You might have a big possession of the ball, shoot a lot, but every shot is blocked or missed. " X shoots but xyz got his foot on the ball..." (just an example).
This is no problem, i think that is actually a real good feature, it force you to let your players play a couple of games in your club to "feel at home" in your team. Just like reality.
(and again, this is a fact, and have been discussed in several threads before)

But my question is how other guys out there experienced the fact of changing formation into a new one.
For example, i have players with skills in multiple positions (they can play MC or DMC for example), and i chose to go from 4-3N-3 to 4-1-2-3 with exactly the same players... for the first time. (after a couple of matches in this formation they should be good at that too of course).

Do you guys have any comments on this?

What is more negative, a new formation or new players? The same effects or different?