The Red Devils often struggled to find a way past teams last term, when Zlatan Ibrahimovic provided the key impetus with 17 Premier League goals, although no other player was able to reach double figures.
"In my other clubs, what I had was more people scoring goals – midfield players scoring goals, wingers scoring goals, central defenders good in the air, scoring goals at set-pieces. We always had that," Mourinho told the club's official website.
"My teams always had the goalscorer - the guy that scores more goals - but then we had the winger that scored 15 goals, the midfield player that scored 10 goals and we had the central defender that scored five goals.
"And, last season, that didn't happen much – we were focused on the goals that our striker was scoring, and when the striker was not scoring, the team was in a bit of trouble to win matches."
Behind Ibrahimovic, United's second-highest league goalscorer was Juan Mata, who contributed six goals across the campaign.