[Armchair historian mode on]

The Byzantines lack a kind of heavy spearman (skutatoi?) - big round shield, long spear, mail vest. They protected the foot archers and formed a base for the cavalry-heavy Byzantine army.

In the same vein - and fully filling the same function on the battlefield - the English really need a "spear" armed dismounted knight (or rather one with a cut down lance). It was the ability of these chaps to see off a cavalry charge that made the French knights start to dismount over the course of the HYW - as indeed other English knights routinely did in the Wars of the Roses.

These are the two big omissions that strike me, because they have such a major (and perverse) effect on the relative strengths and weaknesses of the armies concerned. It's strange why CA model the Byzantines and English as being weak at receiving a cavalry charge, as this was one of the things they had evolved to excel at (providing the base necessary for their archers to be effective against powerful cavalry-heavy foes).

I guess the omission stems from the artificial sword vs spear "rock-paper-scissors" thing TW has going. In reality, the skutatoi and anti-cav English men-at-arms were not distinct units from the sword-armed Byzantine infantry and dismounted English knights depicted in the game. Medieval melee troops usually had spears/polearms and swords (and often more), and could switch between them as desired.

[Armchair historian mode off]