the hitboxes are fine. the facts is people master the stab use by turning and releasing before aiming. i say hitboxes are fine because if you stab while standing still at short range, you glance.
And that is really the problem, with all attacks too.
Sword stabs can last a lot longer than is reasonable (But that could be explained as he is running forward with his sword forward ale Aragorn).
Sometimes you release your block after you've already blocked and the sword remains and stabs you.
Overhead attacks can miss your body, but if they turn into you at any point during the "attack" like after it hits the ground it just slides into the side of your ankle through the dirt and hits you for the same amount of damage.
But with long polearms its the worst. Most of the time when they do it with long spears and pikes the spear is waving it and out of the ground unrealistically. And yes they attack and spin into you, but still its a "stab" and the only part that can stab is way behind me. No matter what direction I'm aiming, if I have a 12ft spear and your 4 or less feet from me it is physically impossible for me to poke you with it.
The only explanation that could be viable, and its flimsy, is that they are holding it close to the point so its only a 4 ft spear and the rest is behind them, but that should require a different animation and an 'x' to change your grip on it.
Thats my QQ for the day.