#2 Killing off games
This probably took more time to take effect but once United started ripping into oppositions, there was no stopping them. Jose Mourinho stopped sending defenders out to shut shop and suck up all the pressure. Instead, he'd send in fresh and brisk legs into the pitch and run the tired opposition defences ragged.
4-0 was, all of a sudden, the new 1-1 and Manchester United became the team you don't want to be trailing at the 70-minute mark. Like Thierry Henry put it,
"If you go 1-0 down against this team, they are going to punish you."
Manchester United had a goal difference of +25 last season. They already have a goal difference of +19 this season and we're only 7 games into the new campaign.
Romelu Lukaku, Marcus Rashford, Anthony Martial, Paul Pogba and even Marouane Fellaini have come to the goal scoring party and are having a whale of a time.