Each Time the the Player is hit, it creates a Wound. Someone that is hit 10 times for 50 HP is still hot 50 times whether the wound is a Deep bruise or their hand is cut off. The dude with 6 HP that got hit for a 10 HP would..? He fell on the sword and it punctured his lung. Get it? I can explain it to you, but I cant understand it for you.
Bwah?
Why can't they just have been hit ten times for varying amounts of damage? Like Hit 1 is a bruise, Hit 2 a couple of broken bones, Hit 3 some stinging because of how light it was, Hit 4 chopped off their leg, and so on.
Magic making them healthier would explain why a morningstar to the face could instantly kill them when they started out, but much later on is barely a scratch; the magic itself eats most of the damage, reducing the actual physical damage they take. Of course, someone who gets scratched enough is still going to die... just a lot more painfully than the guy who got his face bashed in on the first blow.
Your answer doesn't explain how the healing mechanics can have someone sit down, take a breather, and literally heal wounds. Magic infusing the body? Explains that just fine. Their body recharged a bit of magic, the magic healed them. And since we have spells that literally allow magic to heal you directly, it's not outside the established mechanics.
And you can be as snotty as you want, but it doesn't make the nonsense you posted have any logical basis.
It sort of avoids everything with a classic "wizard did it" variant solution -yes I know it's more of "an intensely magical universe did it". One mechanic I liked was called inherent bonuses, with it you could use your model and imagine the warriors effectively imbuing the items they wield with the enhancement bonuses...
It really doesn't help that, with DnD, "a wizard did it" is often actually true.