The materials are still in statu nascendi, but I propose this little tweak to armour system (based on real characteristics):
Let's have Three basic armour types plus one extra: Leather, Chain, Plate, Gambeson (padded armour - basically several layers of cloth sewn together).
Leather - easy to make, easy to carry, good protection against slashing and cutting attacks, no protection from blunt trauma.
Chain - moderately difficult to make (at least talented armoursmith), difficult to carry (will need stronger dwarf - weight of mail rests heavily on shoulders, trust me I've tried), good protection against cutting, slahsing and decent against piercing weapons, no protection against blunt trauma. Let's count cca one bar of metal on each part of set (coif, greaves, mittens, boots) and two for mail.
Plate - difficult to make (at least Great armoursmith), slightly more dificult to carry (surprisingly the main element in movement in plate maille is agility - the weight of armour which is surprisingly small /cca 40 lbs for man-sized one/ and is distributed evenly around the body; you just need to get used to it, saw guy make catwheels in full plate), excelent protection against all types of damage, strong attacks may cause defects and damage to armour that needs repairing at smithy. Needs to be carried over gambeson. Let's count one metal bar on each part (gauntlets, pauldrons, legplates, greaves, helmet) and three for cuirass. Helmet must be worn in combination with some headwear (i.e. cloth cap)
Gambeson - it's basically several layers of cloth sewn together. They were either used solo or worn under chain mail/plate. Solo they offer pretty good protection against blunt trauma, but against edged weapons the protection is poor and does not protect against piercing weapons. Wearing it under armour reduces blunt trauma caused by impact. Laughably easy to make, even by less than average clothier.
Now, by those minimal skill levels I mean minimal fail-free level. Any dwarf under this skill level can try, but has a chance of producing total crap and thus wasting the material (learn by doing mate), that can be melted at smelter later.