Yeah, it's theoretically possible for a vampire to exceed 20 dice, especially at 4th Gen, but in practice, I don't recall anything actually given stats in oWoD that exceed 20 dice. Neither Shaitan nor Kemintiri, the two 4th Gen vampires given actual stats, rolled more than 20 dice, though it's probable that an Antediluvian would roll more. There are also alternative means, and methods, by which a Solar can average about 28 dice via the Martial Arts in Demon Hunter X, which are also explicitly listed as an option in the companion book.... 4th gen vampire ; 9 str, 9 brawl, 9 potence. over 20 dice in the pool.
Other stuff you said ; tons of thanks! Makes sense enough for me, honestly and tons of thanks! I don't mind the 5 limit int heory, though in practice I do like just being innately superhumanly strong or beautiful.