Gotta ask why specialized item choices are in a list you're rating for general usefulness? Pukestabber is a strong weapon in a niche build, utilizing certain consumables in combination with another item choice.
The only weapon I can actually agree with it's place is Mātakau, but that's because it starts at -5% Damage and only gains +1 Pen vs Vessels after dumping 3,000g into it which is utterly terrible.
I completely disagree with the rating for Gladiator Sword, especially if this is geared towards beginners or for a hardcore gamer looking to complete the game and obtain most items to do a proper theory-craft instead of relying on opinion that's marred with untested ratings.
It still has Skrim, providing a +15% Damage increase when wielding a shield, it's not soulbound and it's not tied to certain class mechanics. If you don't use a Shield, it's still better than a Fine Sabre.
It's an everyman's sword (Especially when upgraded with Sharpened Blade) Early game this thing's like an A-tier for generic melee builds. It drops off as you gain access to better gear, but that's the entire purpose of the Gladiator Sword. It's your transitional one-hander as you progress through the game.
You also include Animancer's Energy Blade, which generally by the time you get it you've got other overall more useful selections available.
As far as I can tell, this is marked as an "S" tier weapon, yet it's described as a backup weapon for situational encounters (C or D examples). Wasn't this list supposed to be a general "usefulness" list? The entire point of an "S" tier "general usefulness" weapon would be it's capability of excelling in most scenarios without the need to rely on other conditions/tactical decisions to come into play.
Because it's a Slashing Weapon that deals Raw Damage instead, it's a "S"ubjective Tier weapon, which isn't that good. Just pull out a different damage type weapon that's probably packing some better rider effects per hit, especially since Weapon Modal is "useless" with the Animancer's Energy Blade so there's nothing tying you down to the Sabre weapon type here.
In fact, optimization to cover multiple damage types at once would generally put a weapon above others due to covering a wider variety of resistances.
Based on how you're selling this tier list, Swords of equal quality to a Sabre would be higher tier, unless the Sabre holds a rider effect on hit that supersedes the dual-damage type nature of the blade since it's supposed to be for general usefulness.
But it's not.
You refer to combat mechanics favoring slower attack weapons as a reason for why Rust's Poignard is not S tier, but then list alot of faster-than-normal weapons with action speed increases as part of their abilities in S tier. That in itself is conflicting to why items are, or not are S tier and your bias in favor of low recovery/action speed shows throughout the write-up.
The way grading in this fashion works on the following principle, which you haven't followed if you're making this a generalist tier list for the category defined (one handed melee, in this example).
S - Best
A - Good
B - Above Average
C - Average
D - Mediocre
E - Bad
From everything I've seen out of your tier list, it's in support of a single build style - low recovery, DPS build, graded based on your personal opinion on what's good and what isn't. You've stated yourself some items haven't been tested so it's difficult to really take it seriously or view it as more than an inflated opinion piece to boost views on your media platforms.
Other people have stated it and I'm going to echo the opinion - Tier lists on these types of games are better focused on the role you are filling and how an item could fulfill that role. There's also the issue of early > mid > late game items where some builds will sit on a defensive start and transition into a more offensive design once the items and power level upgrades start to come online.