Pretty sure pep has a much better record at old Trafford than mancini did. We also lost to United fairly frequently under Mancini (including 3 last minute defeats) so I don’t know why this myth that pep doesn’t get the derby like Mancini did comes from tbh. The only time you could perhaps lay the blame at peps door was the 3 2 defeat at home where a win would have won the title. That day he rested a lot of starters but we should have been out of sight at half time poor finishing and bad referring cost us that day not pep Imo.
The way we play was perfect for united, they were most effective when they could sit deep and counter with pace but with the arrival of ronaldo they can no longer do this so I expect us to beat them fairly comfortably in a few weeks assuming ronaldo starts.