Guardiola, in his time at Barca, had arguably the greatest team of all time. Central to that greatness of course was a little Argentinian called Messi. It's interesting though, as he now enters into his 4th season at City, at how much it echoes his time at Barcelona. His points tally at Barca : 2009 - 87pts - 2010 - 99pts - 2011 - 96pts - 2012 - 91 pts. His first 3 years at City : 2017 - 78 pts - 2018 - 100pts - 2019 - 98 pts - 2020 - ?. He took over a Bayern side that had won the title with 91 pts. He kept up the good work in his first season with another win on 90 pts. His 2nd season saw a dip of 11 pts as Bayern won it again with 79 pts. & in his final season he won it with 88pts.
The upshot of that, is that contrary to what you might believe, there is nothing in Pep's managerial history that suggests his teams evolve to bigger & better things in the league. Not forgetting also, that La Liga during his time there, was pretty much a 2 team league, whilst he had very little opposition in Germany either. So taking into account all the teams in the top 6 will probably improve their respective squads, along with City of course. What we can't say with any degree of certainty, is how much impact that will have on those sides, including City again, when it comes to the head-to-heads next season. My guess is, is that there won't be anywhere near the gap we've seen this season between the top 2 & the rest this time next year. Man City may well still finish top of the pile again. But I honestly don't think they're going to continue on this upward trajectory for the coming season.