So do you consider Milan as the third greatest club of all time?
For me this measuring contest doesn't even make sense.
It just depends on the eras anyway, each club has it's time across history with Real Madrid being the best.
Tho, i think in the post-2000 era, Barca & Real took it to another level.
Some of their teams were utterly dominant, 2009 Barca had the previous CL winning United team hopeless and chasing shadows the entire night. It didn't matter who they played, everyone from Division 2 teams to prev-CL winners were hopeless against them.
More than Barca itself, I believe Pep should be looked at as a generational coach who truly took football to another level.