That is not the context in which we are conversing. We aren't talking about what a warlord can/should do. But rather about a claim that Aragorn was somehow being a warlord mechanically when certain scenes played out. That's a forced perspective. It's also not necessary. Nothing in the narrative of that story distinguishes his actions as anything more than a noble ranger roleplaying his character and the other individuals playing theirs.
I don't understand.
The LotR is a novel, written in a naturalistic style. It's not a documentation of the mechanical techniques used to produce a RPG session.
Your argument here is like saying that you couldn't possibly have a LotR-ish RPG in which spellcasting requires a die roll (qv Runequest, RM, BW, or indeed nearly any FRPG but D&D) because we never hear anything about Gandalf's player rolling dice when trying to open the doors of Moria or drive off the Nazgul.
Or like saying that morale rules have no place, because we never hear the narrator ("the GM") rolling dice to see if the orcs or the Nazgul or the balrog fall back.
How would a narration of an event in which a warlord inspires his/her ally to make a charge attack look,
other than like the passage I cited? For that matter, how would bardic inspiration look, other than a narration like the one I cited upthread describing the men of Dol Amroth singing a lay?
Speaking of weak arguments: That's called a strawman.
You misunderstand. An argument can be
weak or
strong not in terms of its validity or soundness, but in terms of the strength of the premises it rests upon or the consequences that it entails. Showing that a class is not
needed is, in this sense, a weaker argument than showing that a class is not
possible: the fact that the argument against necessity is sound doesn't rule out as many other positions as would be ruled out had you shown that the class were not possible.
You tell me. You seem to be one of the people asking for a warlord to non-magically talk someone back from near death. Are you not? I certainly ain't. So why should I be asked to defend such a ridiculous idea?
Again, you seem to misunderstand. You are suggesting that this passage illustrates (i) Boromir having suffered much hit point loss, yet (ii) not being revived by an ally conjectured by me to be a warlord. I am saying that (i) is in doubt, because Boromir has many arrows shot into him, and - whatever exactly that amounts to in D&D - it is not simply hit point loss. Because hit point loss is something that can be recovered from in minutes and hours, but no human being recovers from being shot with arrows like that in minutes or hours, even if someone spends 6 seconds treating his/her wounds with a technologically mediaeval "healing kit".
So unless you are planning on abandoning the D&D damage and recovery model (eg you are going to say that hit points lost to arrow shots can't be recovered except via magic or very extensive healing times) you probably can't extrapolate from the example to D&D mechanical possibilities - unless you assume that, at the time Aragorn appears the death saves have already been failed and at that point the mortal nature of the arrow wounds is narrated by the referee.
How do unconscious (read: unconscious and dying, in many cases) people hear these inspiring words?
The same way that, like Boromir, they speak final words? That is to say, the mechanical state of being
unconscious is not taken entirely literally. I mean, it's not as in the real world no one who is dying was ever able to hear anybody - as if being a dying person also entailed being a deaf person.
Here is another way into the topic: the dying person hears the words the same way that a sleeping person does, or that some comatose people do. The Sleep spell says that "each creature affected by this spell falls unconscious until the spell ends, the sleeper takes damage, or someone uses an action to shake or slap the sleeper awake": presumably, then, unconscious people can (sometimes) feel themselves being shaken or slapped, so why can't they hear inspiring words? The sleep option of Eyebite similarly says that "The target falls unconscious. It wakes up if it takes any damage or if another creature uses its action to shake the sleeper awake"; the sleep option for Symbol has near identical language, while the text for a dragon's sleep gas says that the victim "fall
unconscious for [X] minutes. This effect ends for a creature if the creature takes damage or someone uses an action to wake it."
These all seem to be exceptions to the default rule for unconsciousness that the creature "is unaware of its surroundings", which cause relatively little anxiety or confusion among the player base. I don't see why inspiring words can't be a similar exception.
EDIT: Here is what seems to me the most logical pathway to the Boromir death scene within the general framework of D&D hit point and death rules:
Boromir is pierced by the first arrow. This reduces him to 0 hp, at which point he is dying. (In some early editions he would be dead; those editions, with their mechanics, can't generate the death scene at all.)
Boromir has an ability that permits him to continue acting while dying (say, some version of the 1ASD&D cavalier and sohei abilities).
While in the dying state, Boromir is hit by further arrows. After the first one or two, any further are sufficient to lead to death (eg in AD&D they reduce him below -9 hp; in 5e they cause the death save tally to reach three).
In AD&D, if Boromir were rescued before dying he would require a week's rest, which is at least within the ballpark of plausibility for having multiple arrows penetrate him; in 5e it would be only 6 seconds treatment with a healing kit then a few hours rest to have him back on his feat, which seems quite unverisimilitudinous to me, but is an oddity of that edition.
This still leaves the dying words unaccounted for - both in AD&D and in later editions a character at zero (or fewer) hp, by the rules, can't speak - but perhaps this is just a case of Tolkien's poetic licence, preferring his fantasy to hew closer both to real life and to classic tropes than to the literal text of a rule book.