I'm not sure about the descriptions of Neanderthals presented in this article, but the idea that old tales of orcs and elves originated many millennia ago as descriptions of other human species or other primates isn't that far-fetched.
Using occult chronology, Tolkien's world corresponds to the Atlantis period (the same Atlantis described by Plato). Tolkien took most of the interesting bits from different epochs and compressed them into one short story. The tall people (2x taller than us) in his story are the atlanteans, Saruman and Gendalf must be Narad and Asuramaya and orcs are creatures made by the evil faction during the late Atlantis when the civilization was on decline. The records say, though, that the bad guys won at the end and the atmosphere during that final chapter was shown in the Prometheus movie. All movies and books, though, present a rosy version of orcs and other evil stuff from the records - an accurate picture would be unthinkable even in the book format.