I think it is wrong to say this season will be a write-off, but it's clearly going to be something of a transitional one.
The best teams don't get built in 1 transfer window. There's usually an easily plottable journey as a side gets built up to a point where it's going to win the CL etc. And it's a lot harder to build a CL winning squad than a league winning squad.
I see this season as being not unlike Mourinho's 13/14. New formation, some new players- young players as well. We will still do very well because we are starting from a strong base, but I think there will be some obvious flaws in CM and LB, which, when we fix them next summer, will take the team from challenging for the league/domestic cups to being genuine CL contenders. We can't fix it all in one transfer window - you just can't buy more than a couple of players of the calibre we need in one summer.
This season we will score a shit load of goals, we will see Sterling, Lopes, Denayer and Iheanacho improve drastically and we should win some silverware - or at least get close. It will be a very fun year to be a City fan.