If I have switched positions between two players prior to making a change from balanced to defensive (or any other mentality) the two players will change positions back. This is especially bad if you have made any a substituion.
For example if I want to go forward and I take out my defensive midfielder, put my offensive midfielder on the CDMs position and bring on a forward. If I then switch the mentality after making this change, my forward will play at CDMs position.
This is not good and needs to be changed. There has to be a way to program so the game remembers at what positions the players are playing if you are still using the same formation.