"Greaves (they're supposed to be a kind of armor, so how they move easily is a mystery)"
wut?
Based on the picture, of course it's a mystery. It's not supposed to be a single metal piece for the tibia and the foot. It's either one just for the tibia or 2 pieces(one for the tibia and another smaller one for the foot).
The way it is in the picture of the last page makes no sense. How can you expect to walk and do foot-work correctly if there's nothing for the articulation of your feet!
Edit:
@twinklecake I know, right? Stabbing your sword in the ground is like one of the biggest no-no when it comes to handling a sword.