Charts honestly don't tell you as much as real world experience, and when SCANNING transparencies, the fuji stuff is just way sharper and finer looking at a given ASA, I would even be so bold as to say that the Provia400X is almost as fine grained as E100G and DEFINITELY finer grained than EPT/EPP.
It could be a product of the way the grains/dyes clump together that allows for better scanning even if technically the grain size is the same, I don't know, and maybe E100G would print better on cibi/Ilfochrome but going forward, scanning is the option so sadly that's the comparison that is most valid for most people these days. I have no experience printing either films on Cibi so I can't comment on the grain look of those.