Interesting... PHB pg.197 "Describing the Effects of Damage"
Dungeon Masters describe hit point loss in different ways. When your current hit point total is half or more of your hit point maximum, you typically show no signs of injury. When you drop below half of your hit point maximum, you show signs of wear, such as cuts and bruises. An attack that reduces you to 0 hit points strikes you directly, leaving a bleeding injury or other trauma, or it simply knocks you unconscious.
It seems like the advice in the PHB doesn't align with what you are stating here.
We must be reading different text. It very clearly says that losing the first half of your hitpoints
doesn't show any wounds at all, and the second half produces nothing that couldn't be essentially healed after a quick wash with clean water and a night's rest. It's only the
very last point that is allowed to be any form of meaningful wound, and even that
does not have to be. And even then, by default, the game says such a supposedly "meaningful" wound is gone--so gone you can't even tell it was there--and all you have to suffer for it is being slightly more easily winded (depleting all of your HD means it takes a second rest to recover all of them).
If you prefer to play by the "gritty healing" rules, or want to introduce "real" wounding mechanics, or don't like how quickly non-magical healing works...then the Warlord is, pretty obviously,
not for you, and should be labelled as such. "This class is not compatible with all rules modules, particularly those that affect healing and resting. Consult with your DM before you decide to play this class." It doesn't take more than a couple of sentences to cover that.
And beyond that? Well, I know for a goddamn
fact that inspiration can help you get over being tired but not obviously injured (any amount of HP between 100% and 50%, exclusive), and that small cuts and bruises, even minor real injuries like blisters, can be ignored until you get to a safe resting place (any amount of HP from 50% down to, but not including, 0%). And given that the book explicitly says that your DM
can narrate falling to 0 HP as mere unconsciousness--which I *have* been roused from by outside noise, as have all the military personnel I'm related to--it's perfectly cromulent for Warlords to be specially trained to know how, when, and most importantly
why to resuscitate individuals who have been knocked unconscious.
For DMs that don't want it, give a big, fat clearance to do so. Don't even kid around. "The DM may disapprove of this class or its mechanics. It is not unconditionally approved for use in all games. It is
allowed in Adventurer's League, but this may be overruled at the DM's (or whatever the term is for AL DMs) discretion."
At that point, I ask you: What have you to lose? The rules already say that 100%-50% is
literally not visible, and 50%-0.001% is merely an escalation of small cuts and variably-sized bruises. You literally
can't claim that the book supports treating any HP loss except that from 1 point to 0 points as physical wounding--and even
that doesn't have to be. If the developers give you that special dispensation to say "No, hell no, and never darken my door again!" that you desire,
what more do you need?