I wouldn't describe late Rome as "not big" on cavalry. Certainly they were not cavalry dominant, but they had their share of cavalry units. See the cataphracts

I wouldn't describe late Rome as "not big" on cavalry. Certainly they were not cavalry dominant, but they had their share of cavalry units. See the cataphracts in the Eastern Empire. In the West, there's the famous/infamous "mobile cavalry reserve" that Gallienius setup. I think it's very much worth considering preservation bias. For example looking at wikitaneur as a whole (so mostly one on one, on foot combat), there's basically no material from before the 1400s.