Volantes
Defensive Midfielders (DM)
Positioning
There should be a explicit difference between first and second DMs.
The first should made himself available to change passes with defense and move the ball from side to side.
The second should be prepared to go forward with the ball, playing vertically.
After making their moves, the mode defensive midfielder should be available from behind who received the pass, covering in case they lose possession, making himself a backup.
When a more forward midfielder does the same thing, it should open in the front to receive passes and make a play with wingers and other midfielders.