I need to respectfully disagree too mate. There are very few things I disagree with you on, but on this I definitely do. I think it's letting Ange off the hook somewhat.
I'll start by saying we are definitely short up front. We have no cover for Solanke especially as Richarlison appears to be permacrock. We are also short of at least 1 CB. But...
We have at least 2 FBs for each position Porro, Udogie, Spence and Reguillon. I can't remember a time when we have such a variety of quality in midfield Deki Bentancur, Maddison, Sarr, Biss, Johnson, Bergvall, and Gray. That's a good number of combinations there. It's up to the manager to make best use of that.
I think Solanke is quality, and the 3 CBs are decent. We lack a game changing world class player. But that team is not 11th place in the league quality, winning mainly against other teams that are in crisis.
I get it's difficult to manage 2 games a week. But Ange is an experienced manager, I might expect him to drop a bit in terms of league form while his team gets used to the extra demands but the points per game in the league is really poor. And the form predates us being in Europe. So one could have predicted he would have particularly struggled this season with the extra games.
In the end, BMJ managed it and finished 5th when he had to combine Europe and League. So did Harry. Poch managed it, AVB managed it in his first season. It can be done. It requires a system that doesn't put such great demands on the players and Ange is not willing to compromise on this.