Forget the details, forget the noise. Forget the specifics. Imagine you run a big club on a losing streak. You are looking to appoint a new manager. What do you want, ideally? You want a young manager on the way up, someone fresh, with vision and drive and personality. Someone who could perhaps still be leading the club a decade later.

At the very highest level, most managerial careers are relatively short. The notion of a “proven winner” is a consoling but meaningless shorthand. There is no such thing; everything is fluid, everything is contingent; there is always a context; every career has an arc.

There are exceptions, most notably Sir Alex Ferguson, but few managers last more than a decade at the absolute peak. Management is hard. Football evolves constantly. For a head coach to keep developing occasionally at the cost of what has worked in the past, to stay ahead of the game, is brutally tough and requires not only insight but spectacular will and self-belief.

Everyone tends, ultimately, to self-parody. It happened to Brian Clough, it happened to Arsène Wenger and it is happening to José Mourinho, as they reached not for the best solution to a problem but for the most characteristic solution. It is enormously to Jürgen Klopp’s credit that in his ninth season at Liverpool, after seven at Borussia Dortmund, he recognised that fatigue was gnawing at him and left. And Klopp was somebody of unusual energy.

So ideally you want a manager on the way up, about to blossom, with a full decade of greatness ahead. Identifying that figure is hard. Almost by definition they will not yet have achieved great things. Chelsea’s appointment of Mourinho in 2004 was a rare case of the bright young thing being obvious, having just won the Uefa Cup and the Champions League with Porto. But when they tried to repeat the trick seven years later with André Villas-Boas, after he too had won the Europa League (as the Uefa Cup had become) with Porto, it failed. There are no certainties.

It’s a sign of the lack of football knowledge at a decision-making level at Manchester United over the past 11 years that, until Erik ten Hag, they never tried to identify the rising star of world management. David Moyes was appointed seemingly because he bore a superficial similarity to Ferguson in being Glaswegian; in retrospect it seems mystifying that anyone thought the football with which he had sustained Everton would meet the demands of Old Trafford. Louis van Gaal was experienced and enjoying a pragmatic second flowering, but had turned 63 soon after taking the job; he was never a long-term appointment.

Mourinho in 2013 might have worked but by the time he took over in 2016 he had been through his toxic exits from Real Madrid and Chelsea, second time around. There were plenty of warning signs he was past his peak and the toxicity he naturally brought – which is why Sir Bobby Charlton vetoed an approach when Ferguson left – would not be offset by silverware.

Ole Gunnar Solskjær was a necessary short-term antidote to that, a cheery club legend whose obvious happiness to be there immediately dispelled much of the gloom, but his appointment on a permanent deal was evidence of a board swept along by public opinion, unable to undertake strategic planning. Ralf Rangnick’s bizarre interim status undermined him before he had begun.

Ten Hag seemed a coach of great potential. He had won the Eredivisie three times with Ajax and, after thrillingly beating Real Madrid and Juventus, had taken them to within about 30 seconds of the Champions League final. Not all promise is delivered upon – and he was 13 years older when he took the job than the incoming RúbenAmorim is now.

In Amorim, United finally have one of the thrusting pups of European management, somebody who drew interest from both Liverpool and Manchester City. Not only that, but there is an obvious similarity to Ferguson in that in a league that is essentially a duopoly, he took a third force to the title.

Sporting are much closer to Benfica and Porto than Aberdeen were to Celtic and Rangers, and Ferguson had brought an almost unimaginable European success at Pittodrie as well. Ferguson was five years older when he took the United job than Amorim is now, but he too was a rising talent, who had succeeded with outsiders, ready for his chance in a wealthier, more glamorous league.

As Ten Hag’s example demonstrates, just because a coach has something approaching the desirable profile does not mean he will be a success. Perhaps more troubling for United, though, is the context that surrounds them, the size of the club, the depth of expectation, the incoherence of the squad.

After early defeats by Brighton and Brentford, Ten Hag’s first season seemed to have gone pretty well. Limitations of personnel forced him to amend his approach – as Amorim will have to change his too – and he did it well enough to get United to third in the Premier League albeit off the back of an exceptional season from Bruno Fernandes and a great and, as it turned out, unsustainable start from Casemiro.

He resolved the Cristiano Ronaldo problem with admirable clear-sightedness and, while United were far from spectacular, it didn’t seem unreasonable to think that his second season, with more of his own players, would bring further progress. It did not – and the players he brought in were ultimately what did for him. By the end the steely-eyed figure of that first season had become a risible character, who claimed that conceding 25 chances per game wasn’t a concern and gibbered about the fluidity of Matthijs de Ligt’s blood.

In his fall lies a deeper fear. What if this is just what United do to managers? What if that is why only three coaches have ever won the title with United despite them being the most successful side in English league history, as though the club is a vast and truculent dragon who will submit to being ridden by only a tiny chosen few? What if there is simply something about the United job that is just too big, too difficult, too chaotic? Stare into it long enough, and the United job stares back into you.