1) Pep's False 9 vs Mourinho's 'False' 10
In the forward line, Guardiola is accustomed to playing with a False 9. The False 9, in some ways similar to a more advanced attacking midfielder/playmaker role, is an unconventional lone striker or centre-forward, who drops deep into midfield.
The purpose of this is that it creates a problem for opposing centre-backs who can either follow him, leaving space behind them for onrushing midfielders or wingers to exploit, or leaving him to have time and space to dribble or pick out a pass. Lionel Messi had excelled in this role for Guardiola at the Camp Nou and both Aguero and Iheanacho are capable of playing this role.
The problem for Mourinho in his coaching career has been to include a proper number 10 in his style of gameplay. Be it in Real Madrid with Mesut Ozil or in Chelsea with Juan Mata, he had faced this problem. At United, Mata and Henrikh Mkhitaryan have been used as wingers so far, with Rooney taking the deeper role behind the striker.
He likes a strong forward like Ibrahimovic or Didier Drogba to play as the target-man, whose main function is to score the majority of goals on behalf of the team. Along with Ibrahimovic, Mourinho has Marcus Rashford who has caught the eye of many with his performances.