The issue I have is that many people are talking about 433 as if it's some magic way to get the best out of Pogba purely because of the formation. The three midfielders still generally have somewhat defined roles, with one being the most defensive, one normally being the most offensive with less defensive work deep in the field (ideally you still want them pressing and doing a lot of defensive work higher up the field), and one somewhere in the middle doing a fair bit of both (box-to-box if you wish). Pogba absolutely is best suited to 433, but as the most offensive one with two more solid midfielders beside him. Unfortunately for us Bruno is most suited to the exact same role in that formation.
We could perhaps get away with it if we had hard-working wingers helping out a lot, but Rashford, Sancho, Greenwood and Martial are all fairly defensively lazy.
It wouldn't surprise me at all if we do attempt this, but I think there's over a 50% chance that it ultimately doesn't work and we have to go back to Pogba OR Bruno in a lot of games. I'd love to be proven wrong as being able to fit both of them in a properly working midfield would be brilliant, but I think it's unlikely.
Our pressing is not the worst though, its our playing out from the back that needs more work.
Our pressing as a team is normally quite bad. We are almost entirely reliant on Fred and Bruno (and Cavani if he's in the team) doing it all, while everyone else sits off and lets the opposition play at the tempo they want. Sometimes in big games McTominay does a lot as well, but in most games he's surprisingly poor at it.
With a lot of people wanting Fred (by far our best at pressing) to be dropped, we'll become downright poor at it unless the person who replaces him does a similar amount. And there aren't many around who do that.