Cristiano Ronaldo is currently living proof that Manchester United's problems can't all be solved with one signing, but if it had been the right signing then that could have gone a long way towards sorting out a few of them.
The news that Ed Woodward will finally be departing as the club's executive vice-chairman at the end of this month has understandably led to a wave of wonderings and what ifs, as a man who became a lightning rod for the club's frustrations finally leaves the stage.
Much of that scrutiny and suspicion has been entirely deserved of course, with Woodward cutting a somewhat hapless figure ever since he was spotted on camera taking a photo of the scoreboard when
United lost 2-0 to Olympiakos in the Champions League in 2014
shortly after he took the job.
The photo was, he says, taken as a reminder to ensure that things would never again get this bad under his watch.
Presumably he hasn't taken any of the league table in the years since.
Transfers are of course what he would come to be judged upon, and the Woodward years became known for United's somewhat haphazard approach to doing deals. They would delay and dally and get easily distracted when a big name and even bigger wage packet came along.
Woodward wasn't solely to blame for all this of course, as you get the feeling that United were far too reliant on their name being a defining factor in several negotiations, but a desire for style over substance - and often a lack of any genuine plan - has been what has tripped them up.
At least he tried to get it right though.
ESPN report that Woodward's greatest regret is the failure to lure Harry Kane to Old Trafford at any point during his tenure, and you can certainly see why that is.
Signing Kane would have felt like a very old school Manchester United move, the kind of thing that (then plain old Mr) Alex Ferguson had tried to do with Alan Shearer several years before, and succeeded with the likes of Rio Ferdinand and Wayne Rooney.
Snapping up the best English talent has always felt very Manchester United, and Woodward would have gained some credibility and traction with the fans if he had been the one to mastermind a move for Kane.
Unfortunately for him, Daniel Levy exists.
From the moment of Kane's real breakthrough season in 2014-15 when he scored 31 goals in all competitions, Levy knew just what a special talent he had on his hands. He signed him up to a new five-year deal in the February of that campaign, and by the end of the season he was winning the PFA Young Player of the Year award and sometimes wearing the captain's armband.
United were in the middle of their Louis van Gaal period, and while they would perhaps have wanted to monitor Kane for one more season to see if he wasn't just a flash in the pan (remember those tiresome one season wonder shouts?), they were probably already too late.
Levy had stars in his eyes, a homegrown centre-forward evolving in front of him and a manager in Mauricio Pochettino who was getting his side to play thrilling football. Success looked as though it was within reach.
As Spurs played their best football of the modern era in 2015-16 and 2016-17, United were going from Van Gaal to Jose Mourinho.
Kane would have been the perfect forward for Mourinho to build around but there was no way he was getting him, and Zlatan Ibrahimovic became the short-term solution, one of many that the club have tried to find.
Maybe if Mourinho had worked out for United then Kane could have had his head turned, with the summer of 2018 probably the most promising point for any deal to be done.
United had just finished second, one place above Spurs, but Levy moved again and signed Kane up to a lucrative six-year deal at the time when his love for the club was at its highest. Then Mourinho was sacked in the December and Tottenham reached the Champions League final.
Ole Gunnar Solskjaer's initial, and fairly successful trust in United's young talents meant that he wasn't likely to move for Kane, and nor would the forward want to go there anyway in the summer of 2019 as Spurs had Champions League football and United didn't.
By summer 2020 there might have been a chance had that six-year contract not been only one-third of the way through, and then by last year it was another Manchester club who had turned Kane's head. United's own was turned by Ronaldo.
So Levy has managed to keep Kane out of Woodward and United's clutches in a way that perhaps would not have been possible 20 or even 15 years ago.
Had Woodward pulled it off then it is tempting to think where United would be now, with Kane's goals papering over so, so many cracks that the departing executive vice-chairman has allowed to form.