The fact that Jose has gone will improve us anyway. At the very least Nuno will have us playing with a strategy and game plan in mind. If he can then utilise his man management skills, we are improved already.Whether we are stronger will only manifest in the fullness of time, though I do get your point.
However, your last sentence is just a bit over the top. Last season we were effectively a win or three away from CL qualification, and that was after the wheels fell off midway through the season. We dropped a shedload of points from winning positions due to effectively stopping all of the things that got us into winning positions in the first place. Even if we only reach par on squad strength after this window, the coaching doesn't need to be "God level" to improve on that.
I can accept that certain teams around us appear to have strengthened 'on paper', but who is to say their players will be any better in strengthening them than ours will us?
Nuno appears to be coaching them well so far. It remains to be seen whether that will make the points difference to elevate us back into those CL places we crave.
hopefully the days of lumping it long , hanging players out to dry and deflecting blame left when the ego left the club