Cavalry and chariots against infantry

[Domen]

But far less interesting because they lack (in many cases) the opportunity of direct comparison. Winged Hussars are no Roman cavalry, massed pikemen are no Roman infantry.

But horses are horses. Or maybe not. Maybe they are not "similar" to each other?

One of sources which I quoted says that horses used in Europe during the Roman era were most probably smaller than, for example, Medieval horses. It also says that we don't have enough archaeological discoveries of skeletons of horses from that time to determine this for sure...

So once again lots of questions, but not enough answers.