Of course they are not, but do they have to be? Clearly getting a like for like replacement for Rudiger isn't happening, he's a player in the middle of his prime, at the height of his powers, so unless we're bringing in someone like Koulibaly, we're left with spending big on players who are talented but nowhere near Rudiger (Gvardiol/Torres), or promoting players who are talented but nowhere near Rudiger (Colwill/Ampadu), and my point is leaning on the academy to spread the funds around to other areas of the squad is exactly what we should be doing. I would have thought you of all people would agree given we had a quite a long back and forth in here months ago about the importance of the academy players and protecting the pathway to the first team.
Christensen is different. Kounde will replace him, no problems there. Some might say he's a significant upgrade there.