It's true that Tolkien denied that LoTR is allegory. By "allegory" it's fairly clear that he means allegory in the strict sense. But it's obvious that his writing is "symbolic" or "allusory" in various ways - eg the Silmarillion among other matters very obviously deals with the Fall and Original Sin, both matters dear to the heart of any serious and conservative Catholic thinker.
Ok, sure.
And one of the tropes which the LoTR deploys is the threat to Christendom posed by eastern/Turkic invaders.
I think where we keep running into problems is that you are using your language in ways that I consider extremely imprecise. Tolkien creates a deliberately pre-Christian world with a creator deity largely unrevealed to its mortal inhabitants. There is no element of his middle earth that is analogous to Christendom. Minas Tirith is not Rome. Denethor is not the Pope or the Holy Roman Emperor. It would be at least as correct to say that Tolkien is alluding to the threat posed to Western/Greek philosophy by eastern/Persian invaders and probably more so because the Men of the West at this time may hold some unique knowledge, but its not particularly Christian or religious knowledge. There is virtually no practiced religion in ME, and I think that the best reading of the text is that Westerners don't practice religion because - like Socrates knowing he wasn't wise - they know that they don't know how to do it.
But I think it would nonetheless incorrect to say that that is what LotR is about or that the allusion to the threat of Eastern invasion is means that the Eastern invaders are analogous to particular real-world racial groups and that the story is really about a contest between Europeans and non-Europeans. Tolkien is drawing on elements of the European mythic and historical pallette, including allusions to the repeated threat of invaders to Europe and allusions to Numenorean colonialism and its negative consequences his birth in South Africa and his sensitivity to those issues, but again, Umbar is not actually South Africa or any other English/European colony.
I don't disagree with you that orcs are expressive, as a literary device, of certain human habits of mind. But I do disagree with you insofar as I think that it is significant, in reading and understanding Tolkien, to see that he located this study of human moral failing within a racial and cultural group. Not exclusively, of course, as eg Bill Ferny shows.
Or Lotho. Or Boromir. Or Denethor. Or Gollum. Or the Nazgul. Or Saruman. Or the Mouth of Sauron. Or Sauron himself.
I generally disagree. It's significant to the reading of Tolkien to read into Tolkien racial commentary and doing so fits into the framework of how modern students of literature are taught to analyze it critically, but I think its counterproductive if the goal is understanding Tolkien.
But it's interesting to note that there are no Numernoreans (to the best of my recall) that are orcish in their outlook - even when they invade the island of the Valar, they are motivated by pride - which is, in the right degree, a noble sentiment - and are not aiming at the destruction of beauty and civilisation, nor motivated by the base greed or hatred, in the way that orcs are.
I think for all your recognition of Tolkien's Catholocism, you rather invert the normal Catholic way of looking at the world. How is it that pride has suddenly become a smaller and more forgivable vice or sin that any other? You might as well say that at least Satan isn't orcish in his outlook, because he is traditionally portrayed as being motivated by pride. And furthermore, I think you do the Numenoreans far more credit than Tolkien did to say they weren't motivated by base greed and hatred. The Valinoreans had something that they wanted and which was withheld from them, and they came in their rage and pride to take it.
The story of LotR is about humility. It seems a rather strange take on the story to suggest that Tolkien is somehow writing about the relative nobility of pride or how justifiable it may be in small doses. Frodo was a very humble person, but even his small amount of pride would have been lethal to him had not providence intervened.
If you really want to push this argument, I think you can do a better job showing that Tolkien's treatment of the elves ended up created 'racialized thinking' in D&D than you can with either orcs or humans. In particular, I think D&D elves are blushes on Tolkien elves in a way that highlights the cultural and ethnic divisions that developed between Tolkien's elves (which for Tolkien were primarily interesting as ways of discussing how language evolves) that was racialized when it was recreated in D&D. In particular, I'm thinking about how in 1e AD&D, every single elvish culture required the creation of a new elvish racial group - Sea Elves, Snow Elves, Wild Elves, Grey Elves, Wood Elves, Dark Elves, High Elves, Sun Elves, Moon Elves, and who knows what else.
But I think that has more to do with the cultural baggage of the reader than it has to do with Tolkien.
It's about the literary and dramatic representation of cultural differences.
Is it? When we talk about elves and dwarves is that what is really at stake? Or, when we discuss the Ruml or the Soft Ones, or we really essentially interested in the literary and dramatic representation of cultural differences? I don't think that holds true. I think you could use invented races as less inflamatory standins for discussing racial and cultural differences, but I hardly think that the fact that one author does means that we should force that reading on every invented race we encounter.
Hence the reference to "Victorian anthropology", which (at least as a stereotype) analyses cultural difference by reference to superiority and inferiority
And again, you are improperly conflating two ideas when you do this. This is the heart of my objection to the essay, because essentially the author is accusing everyone who designs and plays RPGs of being racial supremicists or at least tied to racial supremicist tropes. But to ground this back in the RPG mechanics and tropes that are at the heart of this debate, when I assert that Elves have a +2 bonus to dexterity, I'm not really addressing the issue of elvish racial or cultural superiority or inferiority at all. In fact, because RPGs tend to be committed to the idea of 'balance', the presence of mechanical superiority or inferiority in the PC playable races would be considered a negative feature of the system quite irrespective of any percieved commentary this had on race.
he uses as his device for exploring (at least one type of) evil a particular racial concept (roughly, the "eastern horde").
I'm not sure that is the usage he's putting to 'the eastern horde', nor am I sure that the orcs are equivalent to 'the eastern horde'. I think that the Easterlings are probably more equivalent to 'the eastern horde'. The orcs, goblins, and trolls would seem to have a different genesis in Western mythology, like, maybe goblins and trolls.