I keep reading posts about his defensive qualities and that he's solved our defensive midfield issues, but he's not a holding midfielder at all. He has done a decent job at holding in the past, but that performance yesterday was of a disciplined #8, not a #6.
Long term, I think he and Pogba should play as the more advanced players in a midfield three. We need a holding midfielder that can dominate possession and dictate the pace of the game; a successor to Carrick. Then Herrera has the freedom and security to move forward more, and we might be able to press from the front and dominate matches. My only reservation is Pogba's ability to press, I don't think it comes as naturally to him.
All of this would generally be against the ethos of Mourinho, mind.