That game showed what can go wrong in a football game when players can't play their actual positions. It's vital to the team's tactics. This happens when Stuttgart puts Stiller as CB instead of playing him in his actual position as CM. It makes him struggle with his new role, while the fact that Stuttgart still really needs him as a central midfielder remains.
Stuttgart's defense is being gutted. It's worsening with him as CB. He must be subbed as center-back for his poor play. But I'm good with Ito and Anton; they're obviously hard to replace in our defensive line.
Sometimes coaches try to experiment with player positions and in the end some of them are not able to do their job, but it is also not uncommon for players who are placed out of position to end up playing quite satisfactorily. In that match, Stuttgart's coach's strategy was not quite right because he tried to make changes that did not have a good effect on the team. If this continues then I am sure Stuttgart will not get the results they want.
The midfield is very important in determining the direction of the attack and when players do not have a high level of creativity, the game will not go according to the desired scheme. In this case, I also agree with you that the roles of Ito and Anton are still quite difficult to replace by anyone now.