Im with you on that as midfield players should be able to do the lot and I agree on Rodri’s game. The thing is in our system is the sitter doesn’t really have the freedom to move because everyone else around him is. Its different if we played two sitting then one can pick and chose times to go as you’ll still have cover there.
Fair point, but then have a look at us when we were playing at our best at the start of the season. We didn't really have a deep lying midfielder. We may have started with Bissouma in the deepest position, but we were waxing lyrical about him weighing in with goals if his finishing matched his dribbling ability. At times he was ending up as our furthest advanced player.
That mostly arose because of the communication and understanding in our midfield, particularly between him and Sarr. You don't have to be a midfield double pivot to achieve this, you just have to understand that when your midfield partners are advanced, you need to take the responsibility to hang back as support or protection.
When we were purring, all of our midfielders worked in this way. Maddison was dropping in to pick the ball up and dictate tempo. He was slowing the game down then speeding it up at will, and the team responded to that. Sarr and Bissouma interchanged around him, sometimes ahead, sometimes behind, but always with that understanding of how to interact with each other.
That impetus and understanding was wrecked during the Chelsea game, where we lost Bissouma and Maddison to suspension and injury, and we never really got it back until very late in the season.
I don't like rigid roles because they're predictable. If you have a DM, it's just a matter of time before your opposition works out a way to either nullify it or bypass it. However, if you have a fluid midfield, where players can interchange going forward and backwards, you keep the opposition guessing. It's another reason why I hate the rigidly drilled "patterns" that seems to be the latest fad in Football. If you empower your players to find solutions on the pitch, they can adapt to change much better than those who are drilled into robotic movement, rather than thinking on their feet.