Samurai Armor with lower encumberance would just help the balancing (maybe), but not surely thematicness. Ever tried, or even seen, wearing an ancient samurai armor?
On another note, I think it would be a mistake by the devs to start abusing the concept of the gates for many nations. Surely it is entertaining (I came up some time ago with the idea of a dinosaur gate like in Verne, and iirc someone before me with that too) and while it could help the early game of Yomi, and even be quite temathic with the "coming from netherworld" idea, I think going further would just add unbalance to the game... and be probably quite naive.