Permit me to come in the middle here.
The Question of Cavalry is somewhat controversial right now amogst Historians.
many view the use of Cavalry as ShadeHonestus is discrbing.
However.
There is new light being thrown at the use oof it during the Time of Alexander the Great.
Mainly by the work of Robert E. Gaebel.
http://www.h-net.org/reviews/showrev...15411084744526
Which demonstrates that Alexander the Great did in fact use the Hetairoi(Companion Cavalry) in a Shock role.
At this time the subject is controversial, and I hope that we dont go in to the controversy ourselves :)