Comment: Make no mistake, Pep Guardiola is even more ruthless than rival Jose Mourinho
Guardiola and Mourinho may represent different styles, but they share one key quality, writes Paul Hayward
A bonus of importing so many high-end managers to the Premier League is a refreshing rise in ruthlessness. Who could fail to enjoy the squeals of super-agents when their platinum clients are purged by a Jurgen Klopp or Pep Guardiola?
So far, the build-up to Saturday's Manchester derby has fixated on the "rivalry" between Guardiola and Jose Mourinho: the axe that came down in Spain on their friendship.
The United-City duel arrives without the political intensity of the Clasico, but a league which feeds on personality clashes was never going to pass up the chance to frame Saturday's protagonists as two warring princes who moved their battleground to England.
Eventually, we will get around to what each is actually doing in Manchester, rather than what they have already done in Barcelona, Madrid and Munich.
And here, with the Premier League drums pounding, there is one uniting characteristic. It is constructive ruthlessness, which is to be welcomed at a time when famous players and their agents form such deadly duos.
Mourinho is probably right to resent the fawning over Guardiola. It pains him to see City's manager portrayed as the artist to Mourinho's artisan - the keeper of dreams, a leader with soul, unlike United's leader, who is accused of selling his to the underworld.
More than once, Mourinho has implied that Guardiola is every bit as educated in the dark realities of power, just as unsentimental when he needs to be.
The evidence supports the theory. And I mean that as a compliment to Guardiola.
As telling as the "ins" in a summer transfer window sometimes are the "outs" - the players cut adrift for being too old, not good enough or too much trouble. Guardiola has acted with impressive clarity on this front.
Some of his major expulsions were wince-inducing: Joe Hart, especially.
Others were a cause for celebration. Anyone mourning the loss of Samir Nasri?
Guardiola's line went through the names of Nasri, Hart, Martin Demichelis, Eliaquim Mangala and Wilfried Bony. Not one of those ejections can be disputed on pure football grounds, though it would have been nice to see Guardiola have another try with Mangala.
Then came the move that struck at the heart of Manuel Pellegrini's City.
Yaya Toure was unable to earn a place among 17 overseas outfield players in Guardiola's Champions League squad.
Faced with the problem of what to do about a club legend who now runs out of gas after an hour, and who came to unbalance the side when used as a notional deep midfielder, Guardiola chose not to disappoint him by degrees.
Instead: bam, Toure was toast.
The louder the screams of the agents, the more reassuringly powerful a manager clearly is.
Toure's agent accused Guardiola of "humiliating" his client.
At Liverpool, meanwhile, Mario Balotelli's utterly justifiable eviction prompted his agent, Mino Raiola, to complain that Klopp had been a "piece of s***" in discussions about Super Mario's future.
Control comes only with success, Alex Ferguson always said. Without titles, the power is just not there. Guardiola and Mourinho walked into Manchester with the clubs down on their knees to greet them. Guardiola's grasp of politics was apparent in City's long and complicated pursuit of him, which was more merger than appointment. But he already had a history of crushing players who failed to meet his needs.
Mourinho, on the other hand, has been comparatively gentle, casting out obvious passengers such as Victor Valdes and Nick Powell. His most cold-hearted move was to sell or dispatch on loan most of the young defenders promoted by Louis van Gaal: Paddy McNair, Cameron Borthwick-Jackson and Tyler Blackett. To Mourinho, a title-contending back four is no finishing school.
Guardiola flashed his knife, with Mourinho more of a scalpel-wielder, which may betray a greater urgency in Guardiola after his 'failure' to win the Champions League at Bayern Munich. At any rate, Mourinho is right to contest the popular image of Guardiola as an idealist and romantic.
The current line-up of Premier League managers is the best hope for rolling back player and agent power. Of the big names leading teams into action, only Arsene Wenger displays a willingness to indulge stagnating employees.
In a new authorised biography of Andres Iniesta (The Artist-Being Iniesta), the clock is turned back to Guardiola's rocky start in charge of Barcelona, and Iniesta's exhortation to the new boss not to compromise on an ambitious style of play that came to be known as tiki-taka.
Guardiola's big supporter at that time, the late Johan Cruyff, wrote a column urging patience. "He's no novice, lacking expertise, and he is not suicidal," Cruyff said of his protege. "He watches, he sees, he analyses and he takes decisions."
In the same book, Guardiola says of managers: "We're there, vulnerable, undermined by those who don't play, by the media, by fans."
You may not think it, as they strut about on Saturday, but Guardiola and Mourinho are both survivalists at heart. And at this point in the story, Guardiola looks the more ruthless.