Again, a cherry-picked example to cast the model in the worst possible light. The model isn't specifically designed to cover that specific scenario, though. Detailing every possible interaction would be boring and tedious, for very little benefit. Instead, we have a streamlined model that works in the vast majority of cases, with a minimum of fuss. (And which suffers from a couple of nit-picky corner-case problems, if you really want to obsess over minutiae.)
An orc with an axe against a starting fighter is apparently cherry-picked to cast the system in the worst possible fight. An ogre with a club against a fighter with a couple of levels and wearing good but not outstanding armour is apparely a cherry-picked corner case. These are both common monsters against foes of about the appropriate level equipped well within the normal range while the monsters are equipped with the sort of weapons I'd expect them to be carrying. And apparently it's also cherry picking to have any time ever with the PCs not wearing armour.
At this point I am wondering just what exactly
doesn't count as cherry-picking to you. Am I only allowed to use dragons and members of a BDSM club because the game's name is "dungeons and dragons"? I am genuinely serious here in that so far as I can tell you are objecting to some of the most basic situations I expect to come up and claiming that they are corner-case.
And "this common situation would cause broken bones" is not a "nit-picky corner case". It's an expected result. And it's hardly minutae to say that "a broken limb or broken ribs would be a serious problem for an adventurer".
We're not trying to model a substantive hit with an edged weapon that bypasses armor, though. Getting hit by an axe, with no armor (or other factors, like magic) to mitigate it, cannot reasonably result in anything other than serious injury. It's only the existence of armor (or magic) which provides the necessary room for reasonable doubt.
First, your claims are in direct contradiction to the rules. We know the effects of someone being hit by an axe when they aren't wearing armour. Second and more importantly we know that AD&D uses a deflective model of armour where armour frequently prevents you taking a solid hit but the effect of being hit is exactly the same regardless of what armour you are wearing.
The amount of damage an orc does to someone with an axe if they hit is exactly the same on an unarmoured foe as it is on a foe wearing full plate armour.
And what's wrong with that model? It will get us to the same end-point, either way, but with significantly less math required.
Nothing - as long as you don't mind that you're using cinematic action movie physics and have dumped any semblance of reality. Being an explicit game is not a bad thing in and of itself. It just isn't realistic if you value realism.
One of the major reasons why death spirals are pointless is because they tend to cancel each other out, as often as not.
This only applies in some one on one fights. Meanwhile in a many on one fight a death spiral is pretty punishing.
Aside from Daily powers, a fighter who spends hit dice or healing surges to recover is operating at full capacity for the duration of the second fight.
In short they are operating at full capacity except for the top end of their capacity. Right. Gotcha.
Everything that happened to them as a result of the first fight is wiped clean.
And here you are simply misrepresenting the rules. In 4e and 5e
damage is not wiped clean until the hit dice/healing surges are recovered.
(It might theoretically matter around the fourth fight of the same day, or the next morning after six fights in one day, but it's entirely irrelevant now; and it will only ever become relevant for five minutes at the end of the day.)
And this
given the nature of a professional boxing match is simply false. You see boxers have three minute rounds and breaks between rounds - and they also have people in their corner - coaches and people close to them. It would be a foolish boxer who didn't have a warlord or a bard in their corner, even if the bard is banned from active spellcasting. Boxing matches are also long enough that these people can take short rests at the ringside and have their Inspiring Word back up half way through the next round.
This means that when you say "around the fourth fight of the day" what you mean in 4e terms is "somewhere around round 6-8 of the boxing match if the boxer brought their team with them".
At which point the question becomes "did the amateur boxer catch the professional after a seriously challenging slobberknocker or did they catch them after an easy fight?" An amateur who's facing a professional who knocked their opponent out in round 3 is in deep trouble. An amateur who gets into the ring with a professional straight after the judges have scored a 12 round fight is likely to be facing a boxer who is barely standing, has burned all their dailies, can't use Second Wind because they've nothing in the tank, and is down on hit points because they burned through their surges a few rounds back and are barely standing.
The fundamental problem underlying this whole debate is that it's all-or-nothing. Each edition only has one set of rules for healing, without regard for the circumstances in which the HP were lost.
This is yet another false statement.
4e and 5e have at least two sets of rules for healing - it's just set at a cinematic pace. The first rule for healing is getting the character back on their feet (spending healing surges/hit dice to recover hit points). The second rule for healing is recovering those surges - which is a long rest. And I wish 4e had come out with a single paragraph on "tweaking the rest rules" for D&D; I find setting a long rest as a long lazy weekend does good things for the game.
AD&D has only one rule for healing. This is partly for simplicity and partly probably because Gygax didn't think of it.
Games which are less cinematic than D&D and in which the characters are at risk of actual injury rather than merely losing hit points (e.g. WFRP, World of Darkness, Fate) frequently have multiple sets of rules for healing - one if it's hit point loss (or bashing damage) and the other if there are actual consequences or injuries (or lethal or agg damage).
If (for the sake of argument) we take for granted that HP totals include both physical toughness, as well as fatigue and other factors; then a rule that makes sense in the context of a physical hit does not make sense in the context of a near miss, and vice versa.
This is true - and AD&D's rules only make sense if every hit that doesn't reduce their target below 1hp is actually a near miss.
And while it's possible to have a serious world where a number of specific heroes are effectively Made of Iron, it is not really possible to take a world seriously when every single person living there is Made of Plasticine.
Once more you prove that by your own metrics 4e is the most realistic version of D&D. Why? Because it has minion rules - and because PCs have many
many more healing surges than almost all NPCs. Adventuring is its own specialised activity - and that archmage who hasn't stepped outside their library in ten years doesn't have 10hd simply because they are a powerful wizard.