Manchester City must be the ideal opponents. The cost of assembling such a squad boosts the value of any victory over them, yet Roberto Mancini's team are still to show that they are as formidable as Manchester United or Arsenal, the rivals who stand above them in the Premier League. Defeats are always possible but this one was incongruous.

There had been no clean sheet for Aston Villa since the goalless draw with Birmingham City on 31 October and, in theory, they had to take on opponents with enhanced menace now that Edin Dzeko has joined from Wolfsburg for £27m. After going behind to a goal from the debutant Darren Bent, the visitors had the conviction to pin down Gérard Houllier's side but the Villa goalkeeper, Brad Friedel, had no hope of being named man of the match.

City did not force repeated interventions from the American. It sometimes appears as if the contemporary orthodoxies of football are blunting any threat. Virtually all managers at the top level now start with the assumption that there must be only a single striker, since the priority is to get 10 men behind the ball as quickly as possible once possession is lost.

That approach looked perverse when City needed to recover. The afternoon began with Dzeko as the target man and Tevez much deeper. Later the Argentinian was at centre-forward while his team‑mate was sited towards the left. Perhaps it is only nostalgics who wonder whether having them as a real partnership in the middle of the attack, at least for part of the time, might accomplish enough to justify the risk of being outnumbered in midfield.

Mancini is as much in thrall to the orthodoxy as any of his peers and the policy usually makes sense but players and managers now look uneasy when any other method is called for.

It came as a surprise when Dzeko was finally in a position, just beyond the far post, to scare Villa with a header that went wide. The miss occurred with five minutes to go and the cross had been flighted by Adam Johnson, a winger permitted to introduce individuality only as a substitute.

It is right, of course, to agree that the visitors were unlucky. A minute earlier Nigel de Jong had seen his shot hit the post rather than the net when the ball deflected off Ciaran Clark. For all that, City had taken a very long time to find impetus. Villa's key men were the centre-backs James Collins and Richard Dunne, but they were seldom compelled to turn and attempt riskier challenges. Friedel was not especially busy, particularly when Collins and others were getting their bodies in the way of shots.

Bent, signed from Sunderland for an initial £18m, had scored for that club on his debut and also for Charlton Athletic. The forward excels at making a deep first impression but goals continued to mount up at his last club and Villa's record signing, for all the limitations in his play, will be a bargain if the recent ratio is sustained.

His honed reactions settled the match. Joe Hart, diving to his left, could not push Ashley Young's shot far enough and the reactions of Bent were far keener than those of Aleksandar Kolarov as he slipped the loose ball in from an angle. While the Serbia international might have seemed at fault, few defenders possess the sharpness of Bent and the left-back generally had a good game, especially when on the attack. Tevez was unable to connect with his whipped corner kick when an open goal lay in front of him a minute before Bent scored.

No one can dispute that City, fifth last season, are improving. It is an understandable priority for Mancini to insist on strict order when there is a danger that such well-paid footballers could degenerate into self-destructive individualism. However, the team, which is yet to go to Old Trafford, has played two games more than Manchester United and seems lacking in zest now and again.

Even so, the developments are not illusory and City's total of 19 away goals in the League is outdone only by Arsenal. With Mancini leaving immediately after the game to catch a flight to Italy and visit his father, who is ill, it was left to the assistant manager Brian Kidd to speak confidently of the team and of the impression Dzeko has made in training.

Everything may turn out perfectly for City but probably not this season.