We don't seem to actually see a lot of that in Doma. The main samurai we see are Hien and Gosetsu, who don't seem to wear samurai armor like this.

As far as Deltascape goes I don't think much thought went into that other than 'hey let's make a tier of eastern style armor for this raid since there's a lot of eastern stuff in this expansion.'

Anything useful in the 'Doman' gear from HW? I'd have to go check after work, I don't remember personally liking any of those sets and I forget what they look like. Proably another no go like the pvp gear.