I think they make different and nice unit from other "normal" cavarly units. Do they need reworking, you bet. But with little investigation and work they should be included as they were.

Also as I have been told chariots were already kind of "old" during this era and were replaced with cavarly cause their manuverability and speed. I think they should be in disadvantage to cavarly cause they were that in history, but those who play the game and just want to see them on action regadless of this should have right to do so

So I vote yes!