Would you agree or do you think Chelsea and PSG would have been all the same with Guardiola coaching them (all else equal)?
No they wouldn't be the same with their present form. Having money is another thing and how to spend and manage your money is another thing differently.
Gaurdiola is an expereience coach that knows what he needs,we have seen how he has converted Man city into a great club and the strongest presently because he has the skill and knowledge of doing that. PSG is a rich club also with Chelsea but the lack the quality of a good coach. Buying the right players at the right time is what matters alot. Chelsea will be doing better and might have even won EPL if it was Gaurdiola that was their coach,same with PSG. Behind every successful club there must be a great coach and not money. Though.money can turn things around but that is when there is a good manager to make it happen.
That is what I think, too. I don't think that the coaches PSG had were really bad, but Tuchel was good and couldn't do much, Pochettino is average, and Gaultier I don't know really what to think about him.
But I am sure that if Guardiola had ever coached the best PSG team they had in recent years, they would have had a much higher chance of being way more dominant in every single competition and they would have a different squad. He would have added some decisive players on some positions and he would have taken care of a well balanced team.