Seriously. Old-world transplants have lived in the western hemisphere roughly 500 years on Earth, and we dominate the entire northern continent. How is Valenhall supposed to still be colony-sized if it was founded in -473 AR and it's now 4720-ish? Wouldn't there have just been massive wars due to increase in Ulfen population expanding by necessity? Or do the Ulfen all hop ship and head back across the sea?
I would have thought, though, if it mimics the Viking exploration of Eastern North America, it would have been more like 500 years or so before the other Avistani in the 4600's, not several thousand. After almost 5000 years, most Earth cultures have mutated almost beyond recognition, but here's this "colony" sitting pretty in Arcadia for that long, never expanding to become a threat? It's just weird.
I assume that Arcadia doesn't have the smallpox pandemic wiping out 90% of its native population to make way for colonial expansion, to be fair.
Consider all the anachronisms in Golarion living side-by-side. This one thing hardly stands out by comparison.