So does a Katana require less Strength to use than a longsword? Does it require more Dexterity? They were both made in comparable ranges of weight and length. They both need to deal with armor. They can both be wielded with 1 or 2 hands.
Other than a perspective that 'Eastern' combat arts might be Dex-based, why would there be a differentiation between them?
Longsword requires less strength than a rapier, but that doesn't mean they're finesse weapons.
Longsword techniques emphasise the thrust, and the motion of the sword is often within the length of the sword itself. Katana techniques make more use of the insane flesh-cutting capability of its slash, and the centre of motion of the techniques is often outside the sword. *
*Now that is a bunch of generalisations, and both weapons have many different schools that vary as to their use and attitude. There are also a fair number of techniques that users of both weapons would recognise.
In general though, I'd have to say that if you really had to grant a type of longsword the finesse property, the more blade-heavy and slashing-oriented katana would be one of the less-likely examples.
Yes. Obviously you can use a longsword while wearing no armor, just like you can use a greataxe on your rogue. That doesn’t mean it’s a viable build. What I’m getting at is that the mysterious robe-clad, katana-wielding wanderer from distant Kara-Tur, for better or worse, is a popular trope. People like popular tropes to be viable builds. That’s why we got the Kensai in XGTE.
In real life, yeah. But the trope of the robe-wearing, katana-wielding martial artist from the exotic east has very little to do with real life.
True. And as you say, that concept can be catered for with the use of magic: - in the Monk class, which is pretty much ideal for the trope.
True, Ogami Ito only ever wore that one robe. He just killed things faster than they could hit him (so lots of attacks) and had a ton of hit points.
I think that that is it for a lot of those concepts: A very high level character that fights lots of mooks in a setting where HP aren't necessarily meat.
I'm starting to wonder if elaborate discussions of history and gratuitous overuse of the word "arming sword" should be considered thread crapping, because it really isnt contributing anything.
The OP didn't specify a particular reasoning for their suggestion. - a discussion of the realism of it is as germane as the discussion of it in terms of game balance, or realisation of character concepts. "Arming sword" is generally used because the D&D use of "longsword" is pretty imprecise, and so we need different words to distinguish different swords like arming swords, katana, falchions etc that all fall under the umbrella of the 5e longsword category.
I've found the discussion has in general been mostly interesting and informative.
Perhaps if you were a little less vague about how it has been "threadcrapping", then that violation of the site policy could be rectified.
Katanas are not the same as, longswords, they are at least as different as scimitars. They make a fine reflavor for strength based characters but many romanticized samurai (rurouni kenshin, champloo, for instance) are dex based, their slashes relying more heavily on iado and the like. I recommend 1d6 finesse, versatile (2d4) it has the added benefit of adding a two hand build for small characters and dex characters but still is lower in damage than strength great weapons, because it lacks the heavy property for GWM builds.
I've allowed a dual-wielding samurai-type character to simply count both katana and wakizashi as scimitars: - instant finesse-capable reflavour.
And, as you point out, many of the more romanticised later-period "duelling courtier samurai" or wandering swordsmen fit much better with a more monk-like concept - now catered for in the kensei. You can now have that unarmoured, swordsman, able to strike hard with both sword and body despite not being very athletic or powerful.