When they start feeling sorry for you: that’s when you really need to worry. Towards the end of Arsène Wenger’s press conference after Arsenal had been swatted and ragged around the Emirates Stadium like a half-dead bird being toyed with by an indolent cat, there was a strange period where Wenger became unusually angry and incoherent.

Mention was made of the “scandalous” refereeing decisions Arsenal’s manager seemed to genuinely believe were responsible for that supine 10-2 aggregate defeat by Bayern Munich. Now and then his voice clogged a little with anger, or fatigue, but he still seemed to be talking mainly to himself.

At times like these the questioning pack can choose to go for the throat. Instead there was a feeling of awkwardness in the room, a note of tender disbelief at the extent of Wenger’s misguided conviction. Nothing kills like sympathy. Take my arm, old toad, lead me down cemetery road.

This is the end-point Wenger-era Arsenal have now in effect reached. Twenty-one years of sustained, qualified success have unspooled in the past two months into five bruising defeats in seven matches and, more important, a sense of lasting deflation, of a job that is now done and a team that has played itself out.

There is a famous scene in John Updike’s Bech stories where the aged, celebrated, not un-Wenger-like author Henry Bech, suffering from longstanding writer’s block, holes up in a Caribbean retreat signing copies of his long-dead masterpiece, a task that ends a few hundred books short due to a crippling wrist cramp. So it had finally happened, Bech concludes, impotent and spent: he could no longer even write his own name.

This is pretty much how Arsenal looked at the Emirates, a team that could no longer even Arsenal properly, no longer provide the gloss of false hope, the sense that somehow another fourth place will be secured, another season of gilded stasis bedded in.

The absence of heart, guts, spleen and other vital organs as Bayern scored five times in half an hour was the real killer here, evidence that there really is no need to keep marching Wenger around the car park in a headlock. He’s done. Now to the bigger question of what exactly happens next.

It is here that the real interest in Arsenal’s future lies, wrapped up in a secondary battle over the nature and manner of Wenger’s departure. It seems clear the best option now is for Wenger to see out the season, in search of a valedictory fourth-placed finish, then leave with good wishes. For this to happen properly a clear, unemotional assessment of what he will leave behind is now required.

Arsène Wenger ‘provides the same kind of success, the same kind of failings, the same mid-range elite product every year’. Photograph: Catherine Ivill - AMA/Getty Images

Even after such a heavy defeat, talk of disaster, collapse and calamitous underachievement is laughable. On Wednesday morning one newspaper article spoke of “years of abject decline” and of a club in effect reduced to rubble, the ruined citadels, the streets overrun by barbarian hordes. There is, of course, a real frustration at poor decisions made, the rinsing of cash from loyal match-day fans and a reign that has simply gone on too long. The problem with Wenger is that he provides the same kind of success, the same kind of failings, the same mid-range elite product every year. There is an agony of repetition here, a painfully narrowing intimacy, like a middle-aged divorce petition on grounds of repeated failure to load the dishwasher correctly or pick those dirty socks up off the floor.

Actual disasters, though, not so much. Arsenal have gone further in the world’s elite club competition than Tottenham, Liverpool, Manchester United and Chelsea this season. The team Wenger put out in the last 16 cost £172m to assemble, a little less than Real Madrid’s two star players.

The problem is this kind of caution and parsimony has become an end in itself, a winnable game every season.

A more expansive, aggressive, risky approach to recruitment is required, but not quite revolution. Attempts to regear this one-man club too drastically could be disastrous. Imagine, for example, the effects of letting Diego Simeone loose in that dressing room, barking and scrabbling and baring his teeth, given free rein to scrub from the decks all trace of weakness and Wenger-stained flaccidity. The results would at least be entertaining.

Against this there is also the wrong kind of continuity. The idea of another, younger, Wenger-type manager has also taken hold, some hopeful gunslinger with a swag-bag of techniques and theories: spreadsheets, actual tactics, fresher broccoli, more gruelling stretching. The problem here is none of the names suggested is that convincing.

Thomas Tuchel seems to be more highly regarded in this country than he is in Germany. Leonardo Jardim had been around the block before his current success at Monaco. Eddie Howe is bright and compelling but with little relevant experience.

The defender Héctor Bellerín, left, is part of a decent core of younger players at Arsenal. Photograph: John Sibley/Reuters

There is no template for regearing at a stroke a 21-year dynasty. The best approach for now is surely a steady pair of hands, someone experienced and unaffected and grand enough not to have to prove themselves by junking what is still good. Carlo Ancelotti would have been ideal, but that’s not going to happen. Max Allegri, many people’s No1 – not too experienced, not too callow, defensively certain – looks a good choice, were he available.

Plus as ever, of course, the wider issue is players and talent, football’s great non-negotiable bottom line. The playing squad is in need of regeneration. Arsenal’s five best players, the spine of genuine quality at the club – Santi Cazorla, Alexis Sánchez, Laurent Koscielny, Mesut Özil and Petr Cech – are all likely to leave or start to fade out a little in the next year or so.

At the younger end Alex Iwobi, Héctor Bellerín, Alex Oxlade-Chamberlain, Shkodran Mustafi, Jack Wilshere and Danny Welbeck is a decent core to build on. But in the right way this time. Recent signings have been samey and low-grade, just as any new manager will be required to take an axe to the filler, the cushion of B-list Wenger favourites who have to all appearances simply been allowed to graze and drift.

Not, though, in anger, which is the real enemy of progress here. Forget the hysteria for a moment. As the exit music starts to swell it is worth remembering Wenger’s continued presence isn’t an insurrection or a hijack but a function of the bizarre power vacuum above him, the sense of executive lassitude that has fanned his vanities and offered comfort to his blind spots.

If Wenger has stayed too long then it is Arsenal’s board that should be facing the ire of the crowds. Consider this. When Stan Kroenke increased his stake in 2009, shares were valued at £8,500 apiece. Last year Arsenal shares had a mid-price value of £15,670. Here is an investment that has almost doubled while Arsenal have won two FA Cups and become in effect a quietly ticking nest egg, like a buy-to-rent flat where the managing agent is left to do as he pleases as long as the cash keeps rolling in.

It is hard to see any of this in isolation. The task for Wenger’s successor will be not just to re-engage elements of the club’s support and energise the players. But also to connect in whatever way possible with the hierarchy above, to provide a clearer conduit between corporate interests and the more febrile, vital, footballing life on which they feed.