It's not unlikely, actually. Although I haven't looked into the matter myself, there's this meme that if you look back far enough, you should be descended from every person on Earth at a particular time (if they have surviving descendants at all). Simply mathematically speaking. Well, for absolutely every person on Earth that would be a really long time (60,000 years or something). But for someone with Romanian roots to be descended from a powerful Romanian noble 800 years ago (so maybe around 30 generations) is not unlikely, indeed. I think.