If Manchester City also makes changes to their main squad, namely by recruiting new players in the back line, of course this could also make it difficult for opponents to move, especially if they meet Madrid in the UCL next season. If you look at the strength of Manchester City, they are still not strong enough in their defense. So there is still a lot that needs to be changed and Guardiola should be able to see that it is also important for the back line to be given additional new strength from new players who might be better than their current back line players.
Manchester City this season managed to maintain their status as the defending champions, but in the Champions League they actually had to suffer a painful defeat from Madrid in the quarterfinals as well as having to be eliminated faster than the Champions League trophy competition, but even so actually Manchester City has a pretty good squad depth and is even able to make Madrid have to work hard in the two legs of the quarter-final match, So make the winner must be determined by a penalty kick after they draw, so far I think the Manchester City squad is fine and maybe only needs to make a slight change in the main goalkeeper position which is indeed currently often injured.
It's not Manchester City if they are not able to compete with a team of Madrid class, even when Madrid next season has Mbappe, but I am quite sure that Manchester City will still be able to provide strong resistance in the Champions League, but even so, of course, as a team that has a champion mentality and also has high ambitions to win, of course every season Manchester City will try to improve their squad.