I would like to see the notion that Plate armor is the heaviest armor in a campaign, regardless of what it looks like. So, for example, if you are setting your game in the following:
Ancient Rome – Legionary armor (Lorica Segmentata) with the additional greaves and vambraces for fighting Dacians.
Dark ages – Maille hauberk (knee and wrist length) with maille trews.
Chinese Martial Arts movies – ad hoc metal armor for forearms, knees, shins, and a breastplate.
Musket&Pike period -- metal breastplate, greaves, and partial arms (half-plate)
Neolithic -- really thick bear skin