Man City have successfully recruited four new players before the Club World Cup was held, an investment of around €130 million made by Man City certainly wants to maintain momentum in the competition in the following season. Guardiola has been aware of the major weaknesses in his squad so he has moved quickly to plug any holes to maintain stability in his squad.
Spending heavily in the transfer market has never been an issue for Manchester city because that's what have made them to be successful in the past decades, so this four players they have signed already is not a surprise to me.
We all saw how they struggled last season the moment Rodri went on injury, his absence was not just felt but it also affected the rythme of the team play which affected their performance negatively, so since then they have been struggling, added with the fact that their team is full of aged players, so pep guardiola knows that rebuilding of this Manchester city side is greatly needed if they want to compete for the English premier league title once again, and that's what they are doing right now.