I'm also skeptical, but it's about Isco's motivation - not the type of player. If Isco is motivated, he is one of the world's best midfielders. One of Isco's skills, and here he is perhaps the best in the world, is to get away with the ball under pressure. When opponents pressed hard, Real Madrid often solved this with Isco going down into a deeper role, sending Casmeiro the opposite way.
For me, sitting back and absorbing the pressure is not a clever strategy, instead you have to have players who can break through the opponent's pressure = presence. Furthermore, a hypothetical midfield with Gbamin, Allan and AD will be very one-dimensional. None of them are particularly creative, technical and good at distributing the ball. If we are going to play with a 3 in midfield, we need these elements.