I look at the elves in Jackson's movies and how they (almost) all look alike and move synchroneously, e.g., here or here... and my first association is a North Korean parade. Or a Nazi Reichsparteitag.
I don't think the aesthetics of elvish battle formations were ever addressed in the books. Then again, this kind of precision drill does not seem to jibe with Tolkien's portrayal of elves as nature-loving semi-hippies.
Of course, this is not confined to elves. In the Hobbit movies, the dwarves move just the same: in formation, and excruciatingly so.
Has Jackson ever commented on why his battles look like a North Korean parade?
EDIT: Wow, four (net) downvotes and one answer that is well on its way to a reversal badge. So far.
Let me (try to) clarify.
Yes, I do know about phalanxes. In fact, my main pain point about 300 (the movie) was that Leonidas denies Ephialtes a place in the Spartan lines for the entirely correct reason that as a cripple, he would not be able to hold his place in a phalanx... but later the film veers off into the most un-phalanx-like fighting possible, with warriors breaking ranks and fighting single-person actions against what seems to be the entire Persian army. There was almost zero phalanx-type fighting in 300, apart from a few testudo formations (which one can classify as "phalanx-like", even if the Roman legion was really far removed from a Greek phalanx).
All well and good.
However, I have read LoTR a couple of times, along with the Hobbit and the Silmarillion. And I cannot recall an instance where Tolkien implies that anyone in the realms of Middle-Earth fights phalanx-style. He was certainly familiar with the style, as the product of a classical education, but his works of course show far more influences of old Nordic sagas (note his work on Beowulf, or the way he lifted the names of Thorin's company verbatim from the Völuspá, e.g. stanza 11 of the Codex Regius version). And pretty much nobody in the sagas fought a "real" phalanx style (although the Anglo-Saxon formation at Hastings came close).
Instead, the sagas glorified single combat and glorious charges. If anything, the charge of the Rohirrim in the movie was far more in keeping with what Tolkien was familiar with. Along with Théoden's speech, which is quite in keeping with saga-style pre-battle speeches in both content and form. Tolkien was fascinated with the Kalevala, Lönnrot's attempt to collect orally-transmitted folk tales to synthesize a national epic of Finland, and to my recollection (sorry, again no source) at least toyed with the thought of writing LoTR as an analogue for England. Under these circumstances, it simply does not make sense for him to have his elves fight in a style that was used a thousand years before the sagas.
In addition, one far more painful gripe with the LoTR movies (which, admittedly, I did not spell out in my original question) is the way that hundreds, nay thousands of warriors in a kind-of-medieval setting have what looks like identical armor. I understand mass produced identical uniforms in early modern warfare, or in 20th century German SA troopers. (Especially ones selected for filming in propaganda movies.) I find it less in keeping with Tolkien to watch essentially uniformed elves. Especially since mass-producing cloth uniforms for an 18th century army is, of course, far easier than mass-producing metal armor and helmets. Armor can't just be tailored and stitched together. Each suit of armor represents a major investment of time and effort.
On the contrary, I found the scene in The Fellowship of the Ring (movie) entirely in character where Saruman's preparations for war are shown, along with industrial-style production of actual heaps of apparently quickly produced helmets for his troops.
Tolkien's views on industrial production of identical products were rather... negative. See The Scouring of the Shire (the book). One could philosophize about how his experiences in World War I trenches and WWI-style industrialized killing shaped his views of industry, or how World War II and the Nazi atrocities that came to light and were judged pretty much while he was writing LoTR combined to make Jackson's aesthetics jarring to me. Yes, Tolkien explicitly repudiated a facile allegorical reading of his work, where one could instinctively and facilely see orcs and Mordor as "obvious" allegories of the Nazis and their horrors - but then again, I don't think Tolkien had elves in mind that moved with the precision and drill of the Leibstandarte.
Finally, I do understand that CGI producing masses of identically moving clones is easier than hand-crafting every single one, or even filming many actors. What I am looking for is not a technical explanation ("it was easier/cheaper"), but an artistic one.
Did Jackson anywhere, in an interview or some such, address the question of why his battle formations look and move like a modern industrial army (or, if you want, like a phalanx with anachronistically precisely manufactured metal equipment) from an artistic standpoint?