When Sheikh Mansour’s Abu Dhabi United Group bought Manchester City back in 2008, it was hard to see them toppling their noisy neighbours. Manchester United had won their second Premier League title in a row under Sir Alex Ferguson and, though they didn’t know it, were on their way to to a third. The Red Devils had also been crowned Champions League winners mere months previously, too, beating Chelsea in a dramatic penalty shootout in Moscow. Chelsea had tried to topple United after their own takeover, while Arsenal and Liverpool were losing pace with Sir Alex Ferguson’s side. City signalled t…