Low-end, Rudy Fernandez, high end...I don't really know. He's a proficient scorer against high competition, he's a willing defender, and he seems to really love to play, and know how to be a professional.
He's the type of guy the Blazers or Thunder snatch up at the tail end of the first and make other GM's look stupid. I'm tired of looking stupid.
I don't know about Fournier. The low end comparison to Rudy doesn't quite work for me because the weakest part of Fournier's game is his shooting, which happens to be the best part of Fernandez's.
Fournier benefits from the success of Parker and Batum who also were precocious players in the French League but both those guys shot in the high 50s/low 60s on 2 point field goals at Fournier's age. Fournier's percentage was in the low 50s. That could mean he doesn't have quite the athleticism to translate his game into the NBA.
About his league, I don't think the French League is all that strong. The Spanish ACB and Greek Leagues are the two strongest, then I think the rest are watered down. I don't think the French League is so great that their top players would treat college basketball like the "amateur" league it is.