That's why it needs to be someone who provides more options for varying team shape. Rodri has the passing, shooting, positioning, and presence to play further up the pitch. Sure, mobility-wise he's lacking, but for certain games a unit like Rodri farther up the pitch or playing as an 8 could be an asset.
If we bring in a young, mobile, dinho-esque dm then you could play a double pivot (hasn't worked before, but the false nine took a while to work too), maybe you could push Rodri forward like we used to do with Dejong for Yaya (no way am I saying Rodri is the same kind of player, just spitballing). Or even, a young DM could play in the 8 like fernandinho has in the past.
Having players who play multiple positions is how you keep everyone happy.
Pep isn’t gonna play 4231 imo. We just aren’t tactically setup to have a double pivot and any young dynamic midfielder will want to play every week. It’s great to have the option of playing Gundogan or Fernaninstead of Rodri but the names floated here aren’t accepting rotation and occasional tactical starts. We’d have to commit to playing double pivot permanently and I just don’t see Pep sacrificing an attacker especially with how many parked buses we face. We’d have to start overlapping our fullbacks just to have enough bodies forward to trouble a back 10