Some of us did a lot of reenactment over the years so we are aware of the layered armors and how they were worn or better combined into heavier armors.
When you look at the armors in the game you can almost always see various layers like gambeson, mail and then a coat of plates for example. We treat all of the higher tier armors as layered but in order to simplify the game and item management we decided to not model the individiual layers. To be honest we considered a system like you suggested it in an early stage of the game but ultimately we decided to not go with it. We think the additional realism and choice that come with a system like that could be a little too much for the average player.
