Meh. The only reason FPSes feature big men in huge suits of armor is that the concept and gameplay of most FPSes makes absolutely NO sense without them. In real life, people are generally out of the battle, or at least seriously inconvenienced, after getting shot. Even a non-lethal shot kinda hurts. So you need either a really tough military type, or some kind of crazy armor that makes gunshots not so scary anymore, or both, in order to keep with the modus-operandi that is "you need to get shot like 5 or 6 times before you really need to start worrying. Or just 2, if one was a headshot."
I generally call JRPG swords "compensation swords", but that's mainly because I think Marth was a cheap fuck in Melee, and I think that Cloud looks hilarious. But seriously. It's the style. In Japanese games, things need to be larger than life, especially in JRPGs. If we can suspend our disbelief long enough to accept that when combat happens, both sides line up and take turns hitting each other, or that it is reasonable for 2 wyverns and a grizzly bear to set aside their differences and join forces to take you out, then we can accept a sword the size of a small municipality. If it's fun, there shouldn't be a problem.
In other news, I've spent long hours accepting a mushroom-eating plumber who occasionally eats a flower so he can summon fire, or a carrot to become a were-rabbit, or a striped mushroom to become a Bee. After that, a Zanbato isn't too much of a stretch, especially in a world where ostrich-chicken is the primary method of transportation.
All in all, this whole topic screams "Fanboy bait"