Yes, we know that AoE2 is historically, extremely inaccurate. We also know that this is not going to be the case with AoE4. 
The entire team of historians / relics experts, designers, producers and artists has traveled around the world researching civilizations to make sure we get these things first-hand. We want to be faithful to civilizations. Instead of a local expert, we preferred to visit a Mongolian historian in Mongolia to talk about what the Mongols did and what their tactics were. We went so far as to make sure that everything we did was historically accurate