Later sumerian

[badhabum]

From 2334 BCE proto-chariots are available to replace the battle carts .

But I wonder if the replacement is mandatory of optionnal ?

[lionheartrjc]

The replacement is optional.  It is 0-6..
So you can have 4 battle cars and 4 proto-chariots. 

Richard

[badhabum]

Thank you