That true you don't expect that Manchester City should continue to win and have total dominance in the premier League other teams too are preparing and strengthening their squad, so what is happening to Manchester City is not strange to me because over time other teams have improved on their squad and has started competing with Manchester City.
Manchester city should really improved on their squad just the way other teams are doing, you can see Arsenal, Chelsea and Liverpool have signed some new and capable players to strengthen their squad so that they can dominate or compete for the title this season and you can see is working on them especially Liverpool, Manchester city did not make any incredible signings this season which is now affecting the team and also due to Savinho injury you can see clearly that there is no much effect on their on their LW and RW which have also affect them a lot so I think they should mostly improve or buy more players to their squad when the transfer windows open.