First of all, just so it's clear, the primary point of the last post was this: There are no endgame rules presented in either Chainmail or Original D&D, and that goes for either fantasy mass-warfare or dominion management. It's not specifically my point that that's either a good thing or a bad thing. But clearly the impression of such is given, when it's not truly available. (Again, see OD&D Vol. 3 p. 25, as an example.) If we want to be charitable, we could call this impression a "teaser" of things that could come later. If we wanted to get really cranky about it, we could perhaps call it "deceptive advertising" or somesuch. (Of course, I prefer the former.)
Now, as a very minor corollary to that observation, we've also discovered another, somewhat more specific piece of common wisdom that was also erroneous, and that's what I'd like to further highlight here. Throughout D&D mass-warfare writings, we're given the impression that higher-level fighters and monsters can, acting alone, stand against masses of normal troops. ("These fellows are one-man armies!" as per Chainmail p. 30.) This is incorrect, and what I'm interested in here is the proactive effort that was needed to obscure this rather key fact. Here are some case studies.
Case 1 -- Chainmail Fantasy Supplement. Note again that these rules are only for man-to-man action (1:1 figure scale). There is simply no provision available to adjudicate a high-level fighter acting against large masses of troops. Of course, this fact wasn't made explicit in Chainmail, and you have to look to the Introduction of Swords & Spells years later to see it in print from Gygax.
Case 2 -- Swords & Spells. Consider this example from the Introduction (p. 1):
At the scale of these rules a single man can be represented by a single figure on the table. So if one opponent has a lone hero (4th level fighting man) facing several figures of men-at-arms (or orcs or similar 1 hit die creatures), an actual melee can take place. The hero will inflict .40 of the damage shown for a 4th level creature on the combat tables and sustain damage until sufficient hits are scored upon the figure to kill the hero.
Now, there's no need to leave you hanging here, when we can calculate in advance exactly when the hero in question will be killed. And that is (taking reasonable assumptions): In one full turn of melee against one opposing figure. Proof: Assume the hero has average hit points (4.5 x 4 = 18), and is wearing full plate & shield (AC 2). Average damage is shown in the combat table on p. 24 (or, take d6 damage and compute 4/20 x 3.5 x 10 = 7). Note that one full turn in S&S allows 3 melee rounds of attacks (p. 17) and you have 7 x 3 = 21 points of damage against the hero, killing him in one single turn. If you like, feel free to add some hit points for Con bonus, and I'll add the plural "figures" from the quote above to dispatch the hero even more quickly.
Gygax doesn't spell out exactly when the 4th level fighter gets killed (namely: immediately), nor does he explain later on the page why "the admonition regarding single creatures is important" (namely: so they don't get killed immediately). But he could have.
Case 3 -- Battlesystem 2E. (Side note: I love Doug Niles Battlesystem 2E book. It's a really beautiful work, and if it weren't for some very small but critical flaws I wish I could use it all the time.) Consider the same quote I pointed out last time (p. 106):
From a mathematical perspective, the attributes of heroes in a BATTLESYSTEM scenario are inflated beyond those of the creatures in the units surrounding them. However, the conversion is based on the assumption that there is an intangible quality to heroism that exceeds in importance the hero's worth as a fighting machine.
Well, why not spell out exactly the factor by which hero attributes have been inflated? Let's see: A standard figure represents 10 men and is given a "Hits" value 1; hence each "hit" really represents 10 HD total (or more; see p. 105 or my posts from last month, which are comparable). Meanwhile, "All monster types, and characters of the fighter class, receive 1 hit for each 2 Hit Dice or experience levels." For example, a 10th-level fighter or monster (~10HD, comparable to the total hit dice for a normal 1-hit figure), is given 5 hits by this system. In other words: Heroes in Battlesystem have been quintupled over their actual D&D-scale health values. This is to say nothing of their attack values, which are more complicated to compute, but given similar inflation factors.
Niles could have spelled this out, as well, be he chose not to. (The Battlesystem boxed set came with special lead figures for use as heroes/ commanders, and I guess it would be raining on someone's parade if Niles were to suggest that they weren't going to be at all effective standing alone in mass land combat.) Even so, heroes and lone fantastic monsters can be quickly dispatched in Battlesystem by racking up just a few hits on them.
Now, there are a few narrow exceptions to all of the foregoing. One is if the hero's AC is so good that no normal man can hit them. In OD&D this point occurs at AC -2 (plate & shield with +4 total bonus), which is pretty difficult in core OD&D (impossible with a literal reading?), but becomes more likely with Greyhawk and other supplements. (This is possibly countered if you use AD&D's combat tables, count a natural 20 as always hitting, or strictly apply rear/flanking situational bonuses, but that discussion becomes highly edition- or house-rule-specific.) Second would be if the hero/monster is only hit by attacks of a special sort, such as silver or magical weapons, et. al. In these cases a hero figure obviously really could wade through armies of men untouched, until some enemy hero decided to give him chase. But still there is no real contest to play out; the specially-protected hero could automatically massacre an unlimited number of normal men without any threat whatsoever.
Again, I want to clarify that I'm not saying that this affair is either good thing or a bad thing in itself. (In fact, I guess I'd have to say that the realization is refreshing compared to my prior thinking. Numerous new possibilities open up.) Maybe given completely free design capacities you'd choose to have the interaction of heroes with masses one way, or the other. But clearly the impression that heroes can stand against masses doesn't, in general, bear out in play for either D&D or any of the mass-combat games that were later based on it. And that's an error that could have easily been avoided.