Well, suddenly it's all so clear to me. I always thought Murometz was an odd name, assumed it has something to do with the baseball team, never thought to ask as there are so many weird usernames out there. But now... judging from the information I possess, this HAS to be the origin of Muro's name.
And for some reason I want to say he is Ukranian, and not Russian (but possibly both?).