And the 2011/2012 season was particularly dynamic, with City winning the League and United coming second, equal on points but with a worse goal difference. From Wiki.
Manchester City won the title in a tense finale, their first championship since 1968. City's local rivals Manchester United were the early pace-setters, leading the table until October when they drew at Liverpool allowing Manchester City to overtake them. The following week, City increased their lead to 5 points with a shock 61 away victory at Old Trafford, which they maintained until December, when they dropped points and their lead narrowed, but City remained in front until March, when a defeat at Swansea City saw them drop behind United. City's bad form continued for the next month while United went on a winning run, so that with six matches remaining United were 8 points ahead of City and the title seemingly decided. However United, then faltered with a defeat and a draw in their next three games, while City won all three to narrow the gap to 3 points. City then beat United 10 at the Etihad Stadium to move back ahead of United on goal difference. Both sides won their penultimate matches to maintain the situation.
https://en.wikipedia.org/wiki/2011%E2%80%9312_Premier_League
In those circumstances I think it's quite feasible that the Manchester Derby would attract a higher global audience than Utd v Barcelona. Having said that I don't want to get bogged down on this, so it might be an idea just to agree to differ.