Spoiler (click to show/hide):
Was going for the hidden valley, and while yes it's not millions. They did have that large fortress that you came across the wreckage of. That alone probably had a few thousand in it. I was thinking of a population of around or approaching a million.
I don't recall any servant golem, but I will admit I may have forgotten it.
"They are the strongest militarily, in large part due to their high population," Yuna explains, "While yes if we could convince multiple nations to attack them, then we could potentially win, but that would involve convincing multiple nations to forgo their defense, where the centaurs are weakest, and engage them on open fields where they are much stronger. In addition, they aren't exactly diplomatic. No one has met their leader. Hell we don't even know if it is a leader or a council... or what."
Sighing she begins point on the map, "There are dwarves to the south we traded with in these mountains over. There were historic ties with the elves to the west, but after being cut off by the Centaur's conquest of the lowlands here, we have no idea if they exist still, or remember our friendship. There are others, but we'd have to go to either of those or the centaur's lands in order to do so." Looking over the map, it looks like that the nearest caches are close to either the dwarves or elves. The dwarves seem to exist in the same location, though from what you know of them, probably under the caches, while you'd have to check out just out of the elves northern border to look for their caches.
Random person in the comments section of a random hentai manga- "Now I am ashamed of myself."
Me- "Posh, shame is for fools and people with friends... we need no such things, we have the internet."