Maybe when the story comes to be written about this season's Champions League that strange finish to Manchester City's game at Bayern Munich and the awkward moment when it dawned on everyone that Manuel Pellegrini had got his sums wrong will be consigned to the small print. Nobody can be certain everything would have worked out anyway and allegations of amateurishness have to be placed in the context that City have just beaten a Bayern team that accumulated every trophy going last season. They have qualified for the knockout stages for the first time and it is easy to understand why their supporters might be reluctant to feel too aggrieved if they remember it was 15 years almost to the day since Bayern were playing Manchester United and City's opposition was Mansfield Town in the Auto Windscreens Shield, in front of their lowest-ever crowd – 3,007 – at Maine Road.

Yet that does not change the fact that what happened in Munich was a throwback to those days at City when every silver lining came attached with its own cloud, albeit with David Silva and Jesús Navas now in midfield rather than Jamie Pollock and Ged Brannan. Most troublingly, it smacked of a lack of planning and intelligence and, though we will never know what the result might have been in different circumstances, it is tempting to wonder if there is even a flicker of embarrassment on Pellegrini's part considering a fourth goal in the Allianz Arena would have meant winning their qualifying group and a last-16 tie against Olympiakos, Galatasaray, Zenit St Petersburg, Schalke, Bayer Leverkusen or a Milan side that have won only four of their first 15 fixtures in Serie A.

City, as runners-up, will now get one of Real Madrid, Barcelona, Atlético Madrid, Paris Saint-Germain or Borussia Dortmund when the draw takes place in Nyon . Nobody will want to be paired with Pellegrini's often exhilarating side but the bottom line is that everything could have been so much more straightforward if it were not for the manager's blurred thinking, calculating his team needed to score twice more in Munich, then deciding it was probably beyond them, removing a striker for a midfielder and opting not to bring on Sergio Agüero, the player he says is next in line to Lionel Messi and Cristiano Ronaldo.

Sir Alex Ferguson used to call these "senior moments" and he spoke from experience bearing in mind he once spent an infamous briefing, the day before United played Maccabi Haifa in 2002, talking about Hapoel Tel Aviv.

Gordon Strachan was responsible for another one, after Celtic beat United in 2006, not realising that it was good enough to take them through the Champions League group stages until he went in for the television interviews. "I think it was Gabriel [Clarke] who came up to me and said: 'Well done, well qualified'… 'Pardon?'"

Danny Higginbotham also tells a wonderful story about Southampton's first-round tie in the 2003-04 Uefa Cup against Steaua Bucharest, when they drew the first leg 1-1 before losing 1-0 to a late goal in Romania. Strachan was the manager on that occasion, too, and lost his temper afterwards asking his players why, at 0-0, they had been throwing everything forward in the second half, leaving themselves so exposed at the back.

"I was the first person he turned to in the dressing room," Higginbotham recalls. "He said: 'I have to know from you all, did you not realise nil-nil would have taken us to extra-time?' I had to be honest. 'No, I didn't think it was enough, I thought we were out on away goals.' Claus Lundekvam was next and he said exactly the same. He went round everyone and everyone said the same apart from Jo Tessem. 'I understood, gaffer,' he said. 'Nil-nil, extra time, I understood.' Strachan went bananas at the rest of us. He walked out and we felt terrible, all thinking we had got it wrong and let him down."

It was later, once everyone was showered, Strachan came back in with a sheepish look on his face. "Strachan, first and foremost, is the best manager I ever worked with," Higginbotham says. "He just said: 'Listen, something to tell you, it turns out you were right and I was wrong.'" That, of course, is the moment everyone in the dressing room looked at Tessem. The difference is that was Southampton's first time in Europe for 19 years whereas City are supposed to be a serious club these days, dining at the top table and well past the stage where their manager has to put up with cheap shots about having an Alan Ball moment.

Interestingly the German newspapers have been much harder on him than their English counterparts. "Europas Rechenkünstler" – "Europe's Maths Wizards" - was the headline in Süddeutsche Zeitung. The Stuttgarter Zeitung says Pellegrini "embarrassed himself" and Die Welt concludes "the world of football is laughing at Manchester's coach … these mistakes have a tradition at the club." Thomas Müller is widely quoted saying: "I'm not sure everyone knew what was at stake here."

Certainly nobody in the City dugout – and it is some entourage – seemed to cotton on. Up in the press box the member of staff operating the club's Twitter account kept its followers up to speed. Down on the pitch the players were never properly briefed. "We knew roughly," James Milner said. "We didn't know if 4-2 would be enough or if we would need 5-2. We thought it needed to be 5-2, to be honest." My colleagues interviewing Milner report that he still seemed uncertain an hour or so after the final whistle.

Looking at it optimistically, perhaps City will make it immaterial and overhaul whichever of the group winners they are drawn against. They would have to face them at some point anyway, if they actually have serious aspirations about winning the competition, and Pellegrini's insistence that he will not lose any sleep over his mistake is probably based on the fact it is strange a manager can win at Bayern and be held to account for it.

Equally Dietmar Hamann is not one of football's rent-a-quote mob and it is worth listening to him when he describes it as a "ridiculous" and "scandalous" lack of professionalism. Hamann's view is that someone from Pellegrini's backroom staff should have informed him because it is hardly the position of a player to tap the manager on the shoulder and point out he is getting it wrong.

Rafael Benítez, another man who knows a thing or two about winning European trophies, says much the same. It is not an anti-City agenda, before any of their supporters reach for the old default setting. It is just plain common sense. "It mattered – because there's a big difference between winning the group and coming second in the group," Benítez said, accurately. "Just look at the list of teams on those two lists and you will see why."

Hamann overlooks City's record in Europe over the past few years when he says they have cost themselves "a bye to the quarter-finals," but you understand the point. "Cityitis," Joe Royle used to call it, back in the day. At least Pellegrini has a team capable of sparing their blushes.

Keane did not resent Clough's criticism – with Ferguson it is quite different

Roy Keane did not even blink. The interviewer had just asked him to name the best manager he ever played for and Keane was straight to the point. "Without a doubt Brian Clough." Not Sir Alex Ferguson? "You asked the question, I answered you." And he had done so with great emphasis on those first three words: Without a doubt.

He has said it a few times now and, if you were to speak to the three other players who have worked under both managers – Neil Webb, Viv Anderson and Peter Davenport – it is probably fair to say there would be a clear verdict in favour of Clough. And, indeed, that he would have demanded it. "For all his horses, knighthoods and championships, he hasn't got two of what I've got," Clough, the double European Cup winner, used to say of Ferguson. "And I don't mean balls."

Equally we all know Keane's motives when, in the same documentary, he refers to Ferguson as "that man" and breaks into a sheepish smile, almost trying to hide his face, when the interviewer points out the great coincidence that so many of the players he has chosen for his best Manchester United XI happen to be the ones who ended up falling out with the manager.

Brilliant as Clough was, there is also the fact that Keane's time at Nottingham Forest, signing from Cobh Ramblers for the wonderfully unorthodox fee of £47,000, actually coincided with that period – and it had never happened on the Trent before – when Clough sometimes got his plimsolls wet when he tried to walk on water.

Even reaching the FA Cup final in 1991, Clough had already showed signs that he had lost a little of the old magic, never demonstrated better than when he stayed in his seat rather than speak to his players before extra time.

They finished eighth the next season but the following year is when everything unravelled and one of the directors sold a story to the Sunday People that the board had started to think Clough's drinking was out of control.

Keane found him sitting in complete darkness in his office one evening, pretending he was not there because Graham Taylor was outside and wanted to speak to him. "The scene was comical in one way, sad in another," Keane writes in his autobiography. "As I left Brian Clough cowering in his office, I reflected on the toll football could take on one of its most combative characters."

The difference, strangely, is that Clough also used to pan Keane in the media but without any comeback. He punched him in the stomach after an FA Cup tie for costing the team a goal with a careless back-pass.

On another occasion he told the newspapers Keane was a "greedy child" for wanting a pay rise. But Keane just took it. "I didn't resent Brian Clough's criticism of me," he writes. "I never forgot what he'd done for me."

With Ferguson, it is different – nastier, spiteful, as if both of them have blocked out the good times. Neither is probably finished yet either.

London calling in stadium boom

QPR have just announced plans for a 40,000-capacity stadium that will be more than twice the size of Loftus Road and bigger than both the current Tottenham and West Ham grounds. Spurs are planning to upgrade to a new 56,000-seat home and West Ham will be swapping Upton Park's 36,000 seats for 54,000 at the Olympic stadium the year after next. AFC Wimbledon want to move back to Plough Lane in a stadium that would start with 11,000 seats, but rising to 20,000, and Brentford, with an average attendance of 6,700, have plans of their own for somewhere three times the size of Griffin Park. Sorry to be a killjoy but where in London are all these new fans supposed to be coming from?