Cavalry and chariots against infantry

[Sean Manning]

Regarding how animals are - supposedly - too intelligent to be forced to do suicidal things:
[..]A video showing modern horses - so horses far from being trained to do such things (unlike combat horses from the past) - ramming solid objects and plunging into crowd

All videos are of panicking animals. Are you suggesting that cavalry charging into infantry would also be in a state of panic? If so, how would the riders control their horses to charge in the right direction?

Asking for modern pictures of people deliberately riding a horse into a solid crowd is unfair, since even riot police on horseback are usually trying not to seriously injure people. But even panicked horses let us reject "no horse will ride into a mass of men waving sharp pointy things which does not get out of the way as it approaches." But I gave an example of a horse that was deliberately ridden into the Saxon shield wall at Hastings 2006. The rider thought that the spearmen would part and let him through, and the spearmen thought that he would wheel away at the last second.

Incidentally, it is Monstrelet's chronicle which describes panicked horses smashing into the French lines and breaking up their formation (link). I think that he is usually considered one of the best sources for the Agincourt campaign. Sources like this are why Keegan believed that horses did crash into men and stakes at Agincourt.