You're right, mate. I agree with you regarding Manchester City's horrible injury situation. Their failure without Kevin De Bruyne has been difficult. Kevin seems to drive that middle, no? They have so many injuries that appears like they sold their souls to the devil and are now hurt everywhere.
Every club has a tactical pattern of play and there are players who stands as the key or middleman for the pattern to work very smoothly so in times of Manchester City De Bruyne is one of them, his role on Manchester City is very important that his absent on any of there matches could easily be noticed.
So just like you said there failure is just from those injuries, and there is still a likelihood that Manchester city is going to pass through a lot because De Bruyne injury may still last up to two or three months before coming back to the field, however Manchester City needs a better strategy that would help there midfield by performing the same role as De Bruyne.
I do agree that it is not good for City to miss one of their most important players, but they are not at an important stage of the season so far and they can handle it. At league, they are good enough to beat most teams without him, and at UCL they do not face anyone tough so they will go up, which means that this part of the season is not a big deal for them.
But when they get a bit further ahead, when they start to finally play important games at the league which will matter because it is getting closer ,and at UCL when it is playoff stages, we are going to see Kevin De Bruyne start to play, as far as I know he is not out for the season and he will be playing one way or another. I think it should not be all that weird and could be considered alright.