Flick’s actual abilities are an unknown. He’s either a fraud or elite. What he did against Chelsea and Barca in that COVID CL isn’t out of this world because they were either struggling or old teams led by mediocre managers.
I’m going to say he’s a good or above average manager as of now - not shoe in elite though
Tuchel I would rate similarly or maybe a tad higher. Nagelsmann the lowest of the lot.
They’re all better than Xavi but not out and out elite like Jurgen.
Well, you can say the same for every current manager apart from the top 2?
I don't know what you mean by actual abilities but Bayern were ridiculously dominant throughout his reign? Would have won back to back CLs if RL9 was fit in that tie where they absolutely battered PSG.
You want serial winners over multiple jobs who have proven their actual abilities again and again? Pep is at City, Klopp won't come right now, Mourinho is past his peak and Barca won't touch him, Ancelotti is at Real. All the other managers in the world won't satisfy you going by this post.
The kind of elite CV you seem to be demanding is simply too rare a commodity and unattainable for Barca today.