Cavalry and chariots against infantry

[Robert]

Charging infantry with cavalry standing their ground is very costly, as the account of an accidental confrontation between cavalry and infantry that stood there ground entered at the very beginning of this thread shows:

But some realisation of the cost of our wild ride began to come to those who were
responsible. Riderless horses galloped across the plain. Men, clinging to
their saddles, lurched helplessly about, covered with blood from perhaps
a dozen wounds. Horses, streaming from tremendous gashes, limped and
staggered with their riders. In 120 seconds five officers, 65 men, and 119
horses out of fewer than 400 had been killed or wounded.

Gunshot wounds have, because of the bulletspeed, the tendency to numb, as a jacketed bullet passes through the body. This is the very reason police use special bullets designed to flatten on impact without breaking up, so as to impart maximum stopping power. Even criticaly wounded, a adrenalin high assailant will do serious harm before succumbing.
However, this whole thing is now getting into the realms of fantasy. The suggestion of getting horses to trample defenceless mannequins as a way of proving a point deserves total ridicule. We were also originaly talking about the effectiveness of cavalry against drawn up infantry, not the greatness or non-greatness of Roman civilisation set against High Middle age European society. So could we please move back to the original topic within the original timeframe, the Roman army and its known adversaries.