I would love more special units to represent the knightly,chivalric Crusader orders , such as a Templar knight or a Hospitilar knight to the Franks/British/Italian/Sicilians , Templar having the option to convert 1 unit for every charge up and the Hospitilar having the option to heal 1 unit for every charge up.
Or perhaps add these as technologies that can be researched in the Church ‘Templar Order’ & ‘Hospitilar order’ that will grant the already existing knights of the British/Franks/Italians/Sicillians these abilities.
In turn the Islamic civs:Saracens, Turks, Tartars can receive a tech in the mosque called :Jizya tax, for every knightly unit they convert, you receive 5gold.
Perhaps add a technology called Falconry that adds +1 LOS to knights.
For Japanese.
Add a Japanese unit into the barracks , a ninja , that is invisible to the enemy on the mini map. Pop limit of 10 . The Hashasshin (ME) / Shenobi (for Japan) unit can be a stealth unit that has a weak attack but has a large attack bonus against Trash units and kings. Max allowed Hashasshin / Shenobi pop = x5
Becomes visable/spotted when within LOS of Towers,outposts,castles.
Vikings.
I want the Vikings to lose free hand cart + lose Arbalerster but instead have their longboats be able to attack as well as transport units (loses transport ships) and gift them cheap trash units.
In Turn for the Byzantines:
Add a civ unique tech : Justinian Reforms - Sword line +1 Melee armour.
(Optional) Enables the technology of Varangian Guard in Imperial age.
In Imperial age , Byzanitne army gain access to a special unit in the Barracks called the Varangian Guard. - Expensive , slow moving but difficult to convert with a limited build amount.
(Highly loyal guards of the Emperor)
For this the Byzantines Lose Hand cannoneer.
Trash becomes more expensive but Civ gets free wheel burrow and free hand cart.