I am NOT getting myself into this discussion...
I have a similar, yet separate question, which might prove to be good food for thought. I have never read any text or saw a picture that shows a combination of mail and plate armor being worn. Some heavy cavalry
might have worn such a combination
(I remember seeing some EB1 units...), but not infantry, at least I haven't heard about it. Why is that? They had mail, they had breast plates, why did they never combine them? Surely they knew about the positive properties of both types of armor, combining them would be a good idea.
Maybe it was the added weight of an additional piece of armor that caused trouble? Or was it the cost of mass production and maintenance that was too much?