I was trying to make this short quiver in the mural(An-ak third mural, 4C)
and I'm very curious about those [W] shaped pocket on front of the quiver.
I think it's very widly spreadout style in central and eastern asia, even europe, but those Goguyeo army quiver is seems like very short one,
In my test, those front pocket is not so useful, I think this quiver was much longer than picture.

but shorter than turkish style quiver with [w] pocket.
and also, those royal style straped quiver with metal parts is very diffrent style from first picture(army style).
straped quiver needs heavy belt, and it's shape is bowl or box style on bottom, this means straped quiver is can't hold the arrows tightly,
it's just put the arrows and hold the arrow sharfts in the middle,
but this bowl quiver can put whistle arrows or more bigger broadheads.
it must be hunting quiver(and horse riding in the mural?) or ceremonial, not for soldiers and wars.
for example, those eye carved wooden bowl was founded in Sil-la tomb(Ho-woo chong, 4c)
but this tomb's owner was Goguryeo's royal family or high bureaucrat.
so, this relic is Goguryeo's quiver (very similar with horse hunting picture)