Hi there everyone,
GNW Sai uses Tanto, which classifies him as a kenjutsu user. The same applies for Water Main.
What concerns Orochimaru's two versions, it's a thing I'm unable to really specify. I will let our team know about it, so if it will be considered a mistake, there should be something done about it :) If not, then the reasoning would be most likely the usage of that sword in his case.
What concerns Sai and Sasuke's sword usage, Sai uses it always in close combat, and Sasuke was shown using his one very frequently before unlocking better powers, like Susano'o. It was still a prominent feature of his fightstyle nonetheless.
To clarify, to my knowledge, Konoha Traitor Orochimaru is first in chronological order. "Sannin War" refers to the Tsunade and Jiraiya vs Orochimaru battle.
Asuma's tag I'd clarify by the fact that his weapons' extended blades make it into swordlike weapon, while Danzo's attacks are based on wind waves, generated by his kunai, not exactly wind being a blade itself.
What concerns Hiruzen, Yagura, Tendo and Minato, neither of them uses anything remotely close to a sword.
Hiruzen uses a staff, which is also his summoning animal. On the logic of him being swordsman, Temari would apply just as much.
Yagura again, is using a staff. It's nowhere near a sword, and it's not used in a swordlike manner either.
Tendo path of Pain is using black rod receivers, so another staff-like weapon, with an additional piercing power.
Minato's Shiraishin Raijin Kunai are just fancy kunai with his jutsu formula, again, not a sword. Blade, only one of the examples that uses it, but it's still kunai, projectile.
Hanzo uses a semi-ranged weapon, that may not be a sword, but has sword-like characteristics.
Seven Swordsman of the Mist is just a title given, to anyone who wields special so called swords, although those are specifically stated to be just extravagant swords, so that the lore matches the description.
Totsuka blade is not Itachi's weapon. It's his Susanoo's weapon, on top of being a nonmaterial sword, if sword at all. It has no blade, and could be classified as a spiritual sword at most. The same could be said for Hiruzen, that he should be sword user because the Death Reaper he summons has knives. Spiritual nonmaterial weapon that's also not in possesion of it's wielder is not enough to classify someone as a swordsman.
Torune's weapon is Tanto, not a sword to my knowledge, but he barely ever uses it. It's not his fightstyle, in contrary to Sai.
If I missed any clarifications, please let me know. Each character has a reasoning behind itself, to my knowledge, although I may have misinterpreted some.