Anyone else baffled by the scale plate skirts, by the way?
Makes sense. Protects the legs, isn't too constricting and hides your footwork to a certain extent. True, you can't move fast, but that's kind of a bug with any decent armor, and they seem to be heavy infantry anyway.
In fact, these skirts look more like a strange and impractical design. They are in fact more
constricting than traditional leg armour and greatly hinder leg movement.
While wearing such a skirt it's almost impossible to dodge or crouch. It severely limits pace length and makes leaping or running impossible (traditional armor allows all this, but requires great strength; nevertheless orcs are presumed to be generally stronger than humans and Glon was shown earlier running in plate armor). In fact, even using stairs would be a challenge when wearing such a skirt.
Even when fighting in tight ranks, where dodging and leaping techniques are irrelevant, a plate armour skirt gives more hindrance than protection. In a tight battle formation (e. g. phalanx) it is very important that all soldiers march synchronously (that's why drums were employed) and in equal pace.
One of the more efficient and widely-used attack tactics for the tight formations (which were almost always armed with long spears) was charging from a slope, thus gaining speed and impetus. When such a formation collided with any light-armoured opponents, cavalry or a sufficiently small unit of heavy fighters, it just toppled them over and smashed into pieces.
Because different soldiers have different leg lengths, it would be impossible for them to march synchronously, let alone charge, with a heavy metal skirt banging into their knees and making them stumble.
I am pretty sure that no warrior in history, neither male nor female, wore a long skirt when prepared to battle. For example, ancient Romans used to wear long clothes that were somewhat similar to dresses and skirts, but their soldiers wore short clothes, and were bare-legged (except footwear and traditional leg armour). When first encountered with trousers-wearing tribes, they quickly adopted the garment, although trousers were considered a barbaric dressing in Rome and were firstly forbidden.
Such skirts make sense only as ceremonial armour. In the late Middle ages it was not uncommon for rich knights to have large round shields with rich ornaments (although large shields had nearly lost their combat value at that time) and draped cuirasses with metal layer perforated with large holes (so that they weighted less). Such armour may look majestic, but generally is very dangerous to wear in battle.
Please forgive me if some sentences of this text are incorrectly built or unclear, as English isn't my native language. I would appreciate any corrections and try to explain any uncertainties.