Quote Originally Posted by BigTex
Anyways, cavalry in this era werent used like this in the first place. The cavalry's primary goal was to kill the other cavalry, protect the lines flanks. Then to charge the enemies flanks, chase routers or perform a hammer into anvil full envelope.
A very good point actually, save Kataphraktoi, which weren't exactly prevalent in any great numbers as far as I know.

I guess it sort of renders the entire argument moot, but I still think a frontal cataphract charge would disrupt a phalanx, if not break it up completely.