Ludlith clearly states in Japanese that he is a “Pymgy.”
He never says "i may be small, but I will die a colossus,” and the famous line is actually in past tense and much more simple. He instead says:
“Even this Pygmy here was honored to become a lord.”
The Japanese word Kobito (小人) was translated as “Pygmy” since Dark Souls 1. It can mean dwarf, pygmy, small person, elf even, but is more generalized due to the nature of the kanji, meaning more simply “small person."
“Furtive Pygmy” is more accurately (yet blandly) translated as “the small person who nobody knows.” — “誰も知らぬ小人.”
Although both translations can mean the same thing, the capitalization of the adjective Furtive as well as Pygmy has two nuanced effects: it distinguishes him as overly unique, and distances him genetically or essentially from humans, which is not exactly the case in Japanese.
Reading Japanese forums a bit it seems that nobody doubts Ludleth is a Pygmy, but rather the question at hand is whether or not he himself is the first Pygmy, the "small person that nobody knows," or the "Furtive Pygmy." Of course not all seem to agree with this, since the goals of Ludleth and the Furtive Pygmy seem to be polar opposites, making it unlikely to me.
It appears to me that we have every reason to see Ludleth as important however, given the fact that he is a Pygmy King, in a sense, and also the fact that his ring references Gael and the old One from Demon's Souls, and finally because the transposing kiln resembles Fillianore's egg. The Japanese description of his ring calls the Soulfeeder instead a "soul devouring demon / beast." There is blood and ash on his throne, and one has to wonder if his nightmare is actually about him receiving the dark sign itself–a stretch of course.
We also have to ask what the "betrayal" was and if the original betrayal could be related to The Ringed City. Could it be the "shattering the yoke" forewarned in Dark Souls 2, in which the Furtive Pygmy finds the Dark Soul by breaking Fillianore's egg to dispel the illusion of fire and become exiled by Gwyn? In this way, we shatter the last bits of illusion left at the ends of reality until there is truly nothing left but our own hunger or want (or Gael's). Fillianore must be blind, like all Firekeepers, for a leap of faith is required to believe that the egg still holds some glimmer of hope, much like the egg in Tenshi No Tamago (anime). Our shattering it ends any chance for the belief to continue, however.
(I am a Japanese translator at a university in Japan and have never read anyone's alternate Souls translations, so any similarities or similar posts are a coincidence)