This is the lowest moment in Manchester United's modern history - but not for the reasons you may think

Ruben Amorim is Manchester United's worst manager in memory, according to win percentage: and now, he is the architect at the very bottom of the well, chisel in hand.

The Portuguese sat on the bench, head buried in a binder, unable to watch through the cascading rainfall, as Manchester United lost on penalties against Grimsby Town: it's an image of rudderlessness that may well outlive him in the hot seat.

There's a mantra in the modern game, especially among the elite, that process should be valued beyond results – and yet even setting aside the ignominy of a League Two side playing with abandon against 20-time league champions, there is far more to be concerned about than the result. This is a low – but the penalties are merely punctuation at this point.

Manchester United losing to Grimsby Town isn't the low point – it's everything that led them here and everything that will lead them out

Amorim has been utterly misprofiled from the start: it's hard not to feel for him. The 40-year-old swept titles in his homeland with a customary 3-4-2-1 that incorporated superstar talents in comparison to the competition – is that the kind of manager that you get in when your own minority owner, Sir Jim Ratcliffe, himself admits that several of the players are not good enough? Or should you go for someone more pragmatic?

Not to dwell on the thread between Amorim and the greatest coach of his generation, but from a tactical standpoint, this is the reason that Pep Guardiola does not challenge himself at a smaller club. Were Amorim given the resources he had at Sporting – or at least a comparable advantage over his rivals in recruitment – perhaps he'd fare better.

But United have consistently failed in recruitment, too. Instead of hiring a manager who could polish a few average Joes, like an Antonio Conte or a Thomas Frank, the club insisted on the sexy solution, engineering an Arsenal-style rebuild and trusting in a young coach to re-tool the team in his image.

Yet Amorim has failed to show any kind of process worth trusting in almost a year in charge. He has not won back-to-back games. There are tactical black holes, such as failing to create numerical superiority in build-up and suspect spacing between his players. He's competed in big games – but more often than not, that's been due to exploiting opponents on the counter with individual quality, rather than thoroughly outsmarting them.

Ratcliffe has bought into the idea that Amorim just needs better players at his disposal – and so, Manchester United are now a back-three team, against everything that came prior. There are questions over why this shape is quite so imperative to stick with – but the board are seemingly behind revamping the squad to a specific vision that hasn't borne fruit so far.

Worryingly, Amorim has not just failed to adapt to the Premier League, but even suggested that he refuses to tweak his methods. And yet the most troubling thing of all is that the only way out of the hole appears to be for the club to abandon its principles.

United can spend their way out of trouble, but it comes at a cost

Marcus Rashford scored in Amorim's first two fixtures but wasn't wanted by the Portuguese. He's since been deemed good enough to join two Champions League clubs – and now, arguably United's best academy prospect since Sir Alex Ferguson retired can leave permanently next summer for £26m, when surely he'd have been worth nine figures in Erik ten Hag's first season.

Alejandro Garnacho looked to be one of the brightest teenagers in the Premier League when he first broke through at Old Trafford. He's almost certainly not that bad to be cast aside altogether – yet his sale will bring in pure profit when it comes to Profit and Sustainability Rules (PSR).

And now Kobbie Mainoo, one of the best young midfielders in the country, doesn't fit Amorim's vision, either. A post-Grimsby panic to upgrade in goal may well demand his permanent exit.

What is it all for? A United academy graduate has scored in every final that the club have reached since Sir Alex left in 2013 – yet in an INEOS-run world, these assets are almost shinies in a sticker book, worth more for what they can be exchanged for.

That's not a problem exclusive to Old Trafford: it's the way of the modern game. It's not exactly Ruben Amorim's fault either that the only way his bosses can strengthen his team is to jettison those with actual affinity for the club in favour of an endless slew of ever-expensive alternatives that absolutely surely cannot fail this time.

But as United bite the dust in the League Cup before some of their rivals have entered the competition – and the advantages of ‘no Europe’ shrink further – it should become stark and sober to fans. The club have never been lower in the modern age than they are right now: and losing to Grimsby is just the tip of the iceberg.