Based on all the possible factors I’d probably have a hierarchy, with marginal difference between the tiers, except tier 1 and 2, where Real are far and away the biggest club in the world:
Real Madrid
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United, Bayern, Barcelona
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Liverpool, Juventus
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City, Milan, PSG, Chelsea, Arsenal
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Atlético, Inter, Dortmund, Spurs, Ajax
A lot depends how old you are. It’s really hard to balance historical pedigree, with current economic and sporting pulling power. It feels sacrilegious to bracket City and PSG - two plastic clubs - with Milan; but to not do so is ignoring modern reality. Likewise, including Spurs anywhere on the list - a club effectively allergic to trophies - feels strange, but the reality is the strength of the premier league, their income and pulling power all merit them alongside the other teams in their tier.
I do feel that United, Bayern and Barca are just that little bit bigger than Liverpool and Juve. There’s just something bigger about those clubs, whether it’s being treble winners, or the size of the fan base. Maybe harsh on Liverpool but United still have the most league titles, first English team to win the European cup, first and only English team to win the treble, only English team to win the modern iteration of the champions league and Premier league in the same season. United took English teams into Europe and conquered it, and then took them back into Europe and blazed a trail after the Heysel ban. They’ve been the biggest club in England for so long and so often been the standard bearer for English football. Still the only English club to have a player win the balón d’or in the premier league era.