The charge against the Catalan coach - brought not only by sections of the media but by a significant number of match-going City fans - is that he is too attacking; that he refuses to adapt to English football. He doesn't even coach tackles, after all.
It is said that the most successful Premier League managers - like Jose Mourinho and, as last season progressed, Antonio Conte - would prioritise defence when needed, and grind out results in the big games. And often in the small games.
"I think the one thing where Mourinho gets a head start, he’s a very pragmatic manager, he wants to win games, he doesn’t really care how," Frank Lampard, one of the more reasonable television pundits, said in April.
Therefore, it only made things worse for Guardiola when he blamed his forwards, rather than the defence, when City were breached and beaten. This is a man, they say, who does not pay sufficient attention to the uglier side of the game.
Now, he has the finest squad in the country at his disposal, and it would be no surprise if City put six or seven past teams this season.
In Leroy Sane, Raheem Sterling and Gabriel Jesus, who showed so much promise towards the end of last season, City have a blistering attacking trio capable of wreaking havoc for years to come. And let's not forget Sergio Aguero, either.
The forwards will be supplied not just by Kevin De Bruyne and David Silva, but by Bernardo Silva, who City did well to sign so early. Had they been chasing him now, Monaco could probably demand close to €100m for the classy playmaker.
However, Guardiola has shown already that he will not just cram as many forwards into the line-up as possible. Not unless the time is right, anyway.
Guardiola actually had a bigger squad last season but by replacing the deadwood with quality options, he will probably have more selection headaches than he's ever had before.
"Our midfield positions are ‘phwoar!’ Really good," he said on Saturday. Not that he is concerned about the effects of his rotations: "They will all be involved. After that, it depends on them and if they accept my decision or not. If they don’t accept it, it will be their problem not mine."
There were certainly a few quality players left on the bench at the Amex Stadium at the weekend. Guardiola, just like Mourinho, Conte, and indeed every other coach on the planet, picked a team that would win the match, not one that would rack up a cricket score.
"We would like to be a little faster in the last metres," Guardiola lamented after the 2-0 win, "but with the players we had on the pitch, it was even more complicated."
Was the Catalan bemoaning his own selection? Pretty much: "When you have Leroy, when you have especially Raz, even Bernardo Silva, they are guys who are more dynamic than we had on the pitch today."
Why not pick them, then? Because the other forwards were better suited to picking apart a massed defence, while five defenders provided plenty of cover.
The basic principles will be the same whether it's 3-5-2, 4-3-3 or whatever else, but by reverting to the "three-at-the-back" set-up which had fans wincing in mid-winter, Guardiola gave City a solid foundation.
"We were stable," Guardiola said after. "We conceded just one option after one corner and after that, nothing happened
"We are on a good path, still there is a lot to do, but it is important for the goalkeeper, for the defenders, for the way we want to play, [to say] ‘Oh guys, we didn’t concede chances. No scoring chances,’ and that’s good for our future."
Guardiola, surely to the surprise of many, had prioritised the result. The game was not always a work of art, but City were in complete control throughout.
It should be no surprise that Guardiola set out to take control of the game, and ordinarily a manager selecting a team capable of beating the opposition should not be worthy of special note, but the former Barcelona boss' pragmatism has been ignored so often during his time in England.
There is no question that his debut campaign was disappointing, but too often his attempts to get to grips with the Premier League were overlooked.
After all, the decision to ditch the 3-5-2 in the first place was largely ignored. Guardiola switched to a traditional back four for 30 of City's 31 games after defeat at Leicester in December, but still the charge was that he refused to adapt.
There was plenty of attention, however, when City went out of the Champions League at Monaco, ironically on the one occasion when Guardiola's players so noticeably went against what he had instructed.
If Guardiola is to take City to the dizzying heights many expected when he arrived last summer, he will have to convince his young squad to stick to the game plan when the stakes are highest.
Those challenges lay further down the line but, for now, Guardiola's doubters should realise that he is savvy enough to go for substance over style.