[Jasper]

True about the stirrups, although that was because nobody had thought of them. Once exposed to stirrups it's not unthinkable that elite units such as Companions might also adopt their use. I always found it strange that indepdent Heavy Cavalry was better than what seemed intended to parallel Alexander's Companions -- arguably the most powerfull military unit of it's day.

Then again, Arcoscephale already has good troops, and doesn't exactly need the boost. It may be better if they have no cavalry (or equivalently, cavalry so bad nobody uses it).