How were the Hetairoi used (And other heavy cavalry)?

[mikil100]

Now, from my readings across the internet and such (I know, such wonderful sources) it seems that cavalry wasn't really used for "shock" like we see in RTW and ALL of its mods, including EB. What I mean by this is a block of cavalry moving together, lowering their lances and plowing into the enemy infantry (usually in a vulnerable state), letting the lance pierce a man or two and the horse plowing over the rest, causing instantaneous rout.

Now, from what I hear horses were reluctant to charge into a solid block of infantry (even a less solid formation, perhaps?) so how did Alexander and others put these magnificent troops to use, other than other Cavalry to Cavalry fighting and chasing routers/ spread out troops? Were the Hetairoi ever used to plow into even loose infantry formations? What DID commanders do with their cavalry?

Also, how would Hetairoi approach and enemy fleeing them? Did they ever use an overhand spear motion?


PS: I don't just mean this for Hetairoi, any civilizations cavalry is up for grabs, but the most pressing question to me is Hetairoi.. (In NO way do I doubt their potency, I just.. want to be further enlightened on how these elite troops did their business so effectivly)