Interesting, makes sense. I was always onboard with Rabiot for the record, I'm more trying to get my head round Mount and how it would work.
Mount makes sense if you add the idea of changing systems between games or within games, at the minute we have no flexibility. If you have Mount, Rabiot, Bruno, Eriksen and Casemiro, you open your options:
Rashford-------Bruno-------Antony
------------Rabiot-------Casemiro
Rashford-------Bruno-------Antony
------------Mount------Casemiro
Rashford-------Mount-------Antony
------------Rabiot-------Casemiro
Rashford-------Bruno-------Antony
------------Rabiot-------Mount
Rashford----------------------------Antony
-------Rabiot---Casemiro--Mount
You end up with more balanced and viable options. Now people may have an issue with creativity but if it's paired with someone like Kane and a Bruno that has a bit more freedom to focus on creation, it can allow us to maximize what we have. If the target was Osimhen or someone like that then I would really prefer a more adventurous passer in place of Rabiot.