This "ceterus paribus", all other things the same approach is what I am not agreeing with. Yes I have seen Messi playing than, still he was not as good as he is now, he was also better in the upcoming years. I know Iniesta's godlike performances, because I was part of those guys who believed that Iniesta was the best player on the planet after Messi. The thing is, you have the feeling that these players all of a sudden get "better" or are in their "primes". Just a year before that, Rijkaard did not manage to win the title (3rd with 67 pts), he had Iniesta, Xavi, Messi, Puyol, Abidal, Yaya, Henry, Eto'o, Ronaldinho (yes more in the bars than anywhere else) and Deco. You exclude the fact that players adapt to each other as well as teams (against each other). Raw talent of our players back than are super important, but that is not the only thing what makes them "win" trophies and here instead of some other force, managers and their managing team come into play. They facilitate the good players and lift them to their godlike performance (in some cases), in other cases, they can't really make use of so much talent (Löw, probably having a very strong side for years, only managed to win a WC).
I do not even deny that the collection of players were better, but this so called collection of players is also part of the managers' job to have. Again, Alves, Pique, Busquets (promoted) etc. were brought in by Pep. There's a "documentary" on Youtube, players like Valdes, Iniesta, Xavi and Puyol talking about Pep. Although surely there's some confirmation bias in there, you cannot deny that Pep's influence on this team and the individual players was incredible. Some even say they have learned how to play football under Pep.
In the CL: Drogba (prime or not?), Lampard (prime or not?), Essien, Terry, Anelka etc.
You have a talent pool in a certain period of time that is allocated among the best teams in the biggest leagues. That talent pool may be different now (according to you stronger), it does not change the fact however, that the best players between 2008-2011 were also allocated among those very same teams (Madrid, Barca, Bayern, Chelsea, Manu, PSG did not have its financier back then). No PSG was not as strong, but where did PSG get their current players from? Big money teams have a tendency to attract more talented players at once, but I still don't really see PSG as a strong force. Take City for example, although they have managed to win the EPL, they seem to be super poor in the CL (getting knocked out even in the group stage).
Your initial argument was that Lucho pawns Pep, which I do not believe at the moment. If we come back to Lucho: Suarez mentioned that it was Messi who told him to stay at the "9" position and play there - I read this as: Lucho adapted the team accordingly.