Hum... how could I say that? When I'm listening some americans speaking about Europe, there are a lot but really a lot who don't realize it is not a country, then they do a fast and utterly wrong parallel between USA and Europe. I was only referring to geographical, since FFXIV Europe has two worlds (Chaos and Light).
If you wish I explicit things. I'm french and in my experience, and some feedback I had, it is not rare to see german players trolling french players (the opposite is true). A lot of dutch and german don't like french people (the opposite is true). And considering, as you say, culture, language and mindset, from a country to another, we don't have the same school system, we don't have the same traditions, we don't have the same habits, of course, we don't have the same language that leads to the consequence that if we have some shared traits of culture (christanity -thought including Russia, we then have four different christanity-, some food, some arts) we do not have the same mindset on a lot of topic (the UE as political entity is a fair demonstration of that).
So when NA players pretend it is easy to build a party for Ex and Savage, they are missing a big difference between UE servers (we have two worlds and more than twenty languages) and NA servers (three worlds, four main languages considering South America : Spanish, Portugese, English and French). Worlds and servers are shorter with pretty much more languages even only considering the most used. Since again, a lot of players are not that comfortable to play in english, International FCs we could expect are rather anonymous. We find more of them... on japanese servers (but latency... for Savage or Ex... hem...).