That's every single GR tournament finals since 2008 or so. I can't speak to any of the names before around 2009, but of the finalists listed there, the following were from North America:
Morello (Maybe? Can't remember for sure)
That's 4 players out of approximately 33 different players who played in all GR tournament finals between 2009 and 2012. Of those 4 players, only ntd won a tournament. That's 12% of the tournament finalists over 3 years. The other 88% were mostly European and Russian, with two Koreans.
More recent results, from the last SNF season...
10 different players played in broadcasted games (semi-finals of a contender bout or higher). Of those 10, 9 were European for sure, and the last one, Twister,
Elite Mod tournament, the last real CoH1 tournament. No North Americans in the top 8. Pretty sure there aren't any in the top 16 either, but I don't know all the names there.
So yeah, there's your facts. CoH has been a European-dominated game for at least the nearly 6 years that I've been around for.