AoE1 has a lot less units. Adding the Camel Armour class to the one Camel unit shouldn’t be hard.
The same for thing like Elephant or Cavalry Archer armour classes.
Maybe RoR does. That’s more of a map feature then a civilisation feature, isn’t it?
Good chance they added that to RoR.
The Stone Thrower line outranges towers in AoE1 so why shouldn’t it outrange AoE2 Towers and Castles?
This is definitely the hardest part.
For a lot more analysis of how to balance AoE1 against AoE2 in a crossover mode:
AoE1DE should become an AoE2DE Expansion