Anyway, regarding mechanics: I agree with your points, but I draw a different conclusion from them. I especially agree with your statement that "[healing] is about recovery." That's an important distinction, because in the fiction that inspires the class feature we're talking about a character doesn't recover from being damaged, rather the character goes on despite being damaged.
For the most part, I believe you and I are on the same side of this debate, but I disagree with the perception you express here.
I've touched on this before, but I think it keeps getting lost in the mix.
I agree completely that "healing is about recovery", but I disagree that Warlords don't stimulate recovery from damage, or that the fiction that the Warlord is based on doesn't support this.
First, there is no one source of fiction that a Warlord draws on. Some are consistent with your statement, some are not. For instance, the example of Sarah Connor and Kyle Reese is one such fictional source that is contrary to your statement. Reese does far more than just soldier on despite being wounded. His energy level returns to almost normal. His ability to fight returns to almost normal. He is no longer in danger of succumbing to his wounds. That is most certainly recovery from damage - from a fictional and real-life perspective.
This highlights the second part, as you've said, damage is not just wounds. Wounds themselves don't kill. Wounds themselves don't
cause death. What causes death is the loss of
homeostasis.
Homeostasis is the ability of an organism to regulate its functions; things like maintain blood pressure, blood volume, heart rate, circulation, neurological activity, waste processing, resist toxins and agents, etc.
For example, a vicious sword cut doesn't kill. The body can still structurally/mechanically continue to operate. What fails is the bodies ability to maintain blood pressure and volume. When homeostasis is sufficiently lost, the organism ceases to function (usually heart failure and/or brain death).
Even a heart attack itself doesn't kill. A heart attack leads to the inability of the heart to maintain blood flow. Homeostasis is lost as a result, and the organism dies.
Inability to maintain homeostasis is also damage, and is not necessarily precipitated by injury.
In the case of Reese, he is suffering from an accumulation of
damage: exhaustion, blood loss, circulatory shock from extreme pain and intense prolonged fear, actual structural damage/wounds, etc. He passes out because his body is losing homeostasis.
When Sarah yells at him using mental triggers he's conditioned to respond to, his brain responds by stimulating the production of epinephrine (adrenaline), serotonin, dopamine, norepinephrine, and others.
The epinephrine immediately raises his heart rate and blood pressure. It was low before, the primary reason why he passed out, and is now back at normal levels.
The dopamine
motivates Reese - in this specific circumstance, motivated to fight and survive.
The norepinephrine
focuses Reese - allowing him to focus on the threat at hand and respond accordingly - allows him to access and utilize his training and knowledge to fight.
The serotonin floods his system to aid in blood clotting, vasoconstriction for purposes of homeostasis, and generates a sense of optimism.
As these hormones/neurotransmitters flood Reese's body, he revives - recovers - and gets back in the fight.
Homeostasis, though being supported by a surge of chemicals, has been restored.
And here's the kicker, just because homeostasis is being directly stimulated, doesn't mean that homeostasis won't remain after the surge is over.
If, while the surge is taking place, the body is able to clot enough to stop or limit blood loss, and thus allow for functional blood pressure without adrenaline stimulation, then homeostasis will be maintained.
The body has
recovered from damage.
Now granted, in real life, there is a significant
if involved. Such as,
if sufficient clotting hasn't taken place, homeostasis won't persist after the adrenaline has worn off, etc., etc.
But D&D doesn't differentiate damage this way. It doesn't get this granular (and doesn't use persistent wounds or their effects - so we have to ignore this for the official rules - though I think it's inclusion would solve a lot of the disconnect being experienced).
We use an abstract quantification that encompasses all of that so we don't have to get that time-consumingly involved. As long as one understands Hit Points to be an abstract quantification, it supports any level of granular examination or interpretation one wants; including recovery from damage because somebody exhorted another to do so. Anyone who says there is only one interpretation of Hit Points - only one thing they represent and only one way to think about them (not you, epithet; I'm referring to a certain height-challenged divine-wind) - they simply couldn't be more wrong.
So, in conclusion, Warlord action can stimulate recovery from damage. It's present in both fiction and real-life.
However, I will stipulate that just because recovery from damage
can occur, it's not guaranteed.
With that in mind, I propose this for both proponents and opponents of Warlord healing:
Would it be acceptable - a tolerable compromise - assuming the use of real Hit Points rather than Temporary Hit Points - for Warlord healing to require a saving throw after a certain amount of time or following combat, or risk reverting to the previous Hit Point level unless one has received magical healing or use of a healer's kit?
(A saving throw that reflects the uncertainty - the lack of a guarantee - that homeostasis can be maintained.)
[video=youtube;N71d7BF1fZ4]https://www.youtube.com/watch?v=N71d7BF1fZ4[/video]