If an "analysis" makes the best manager around look like an imbecile who is completely out of his depth in the CL (knock-out) games, then something with the "analysis" is seriously wrong.
Many posters on here say Pep's a genius but a bit of an idiot in the CL. That's very, very stupid.
So, why did Pep make that "tactical mistake"? Here are some possible reasons.
First, Rodri showed sings of losing form in April/May, despite having an excellent 2nd half in Paris. Fernandinho was far from being as good in the 2nd leg vs PSG as he was portrayed. The first half at the Etihad was poor, PSG hit the bar and were the more dangerous team. Dias was MOTM because he had a lot to do, more than in Paris, despite PSG being without Mbappe! Also, Mount was toying with Fernandinho at Wembley, where Fernandinho had a pretty poor game vs Chelsea. Also, the referee Lahos might have shown Ferna a yellow pretty quickly
Second, Pep wanted to surprise them. He won 14 from the previous 15 finals he participated in! Anyone who thinks Pep has a problem in finals doesn't know what he is talking about.
Third, Pep doesn't want just to win, he wants a spectacular win. That may be interpreted as arrogance and as an weakness. But if Pep wasn't like that, City wouldn't have broken so many records playing fantastic football.
Fourth, Pep started Sterling for he was afraid that James may create a lot of problems to Zinchenko and wanted to engage James with a forward, and when James attacked, Sterling could be isolated one vs one with Azpi who is much slower than Sterling.
Fifth, Chelsea play a completely different system compared to PSG. Why do people think that what worked vs PSG would have worked against a team with a much better defensive organisation than PSG?
Sixth, the system we played was heavily used in January and February when Kevin was injured, and also vs Spurs at Wembley, but back then Gundo played Kevin's role and in the final he played Rodri's role. The system wasn't new, we used it at Anfiled, Old Trafford, Wembley, etc.
Etc.
The idea that Pep was an idiot without any good reasons to play the formation he did is daft. It wasn't a clear tactical mistake. It didn't work out, but I think the reasons had more to do with the fact that the pressure of being favourites got to the players, they didn't handle it well at all.