I don't think in normal pictorial use one would really see a difference between various lines of modern MF lenses, especially if you're stopping down to gain depth of field.
All other things being equal, it depends on how much magnification the image is undergoing. At web/monitor resolutions, you're pretty much right. But start punching out 11x14 or 16x20 prints and the flaws in the optics start to show up, at least for some cases.
My 'Blad lenses just blow away Yashica TLR, Mamiya TLR, and Mamiya 645 at larger magnifications.
OTOH, the Mamiya 7 is a close competitor at 16x20 at least, arguably because of the increased format size - but those lenses really are something to behold. Similarly, the Fuji GW690II I have here punches well above its weight, again probably because of the big negatives.
I was also shocked to discover just how well the Fuji GA-645Zi negatives compared to comparably sized prints from the 'Blad - bearing in mind that a Hassy negative is approximately going to be 645 if you want rectangular prints.
But it's also not just about resolving power and contrast. The Hassy lenses are magnificent but have a kind of clinical quality to them that does not always serve the subject well. By comparison, my old 50mm Collapsible Summicron on a Leica body has a "look" that is unmatched, notwithstanding the fact that neither the format nor the lens itself are remotely in the same league as the Hassy. I cannot exactly explain this, but that old 1955 Summi has a kind of "depth" to the look that I cannot quite explain.
Similarly, my uncoated 1945 50mm f/3.5 Elmar has a kind of flare behavior that's haunting and beautiful.
I've seen many other examples - an old Commercial Ektar vs. a modern Schneider on a 4x5 leaps to mind.
All that said ... I still own a Yashica-MAT 124G and Mamiya Universal because - optical limits aside - they make really nice pix.
It takes many brushes to paint great pictures.