I don't believe them to be the "Smartest" they all have a high post counts, which means they have experience.
They've probably been in a vast amount of debates and probably found out allot of new knowledge. It's probably gotten to the stage were they know everything about their favorite character and the pages of the scans, which is why when you debate with them you don't have as much knowledge, and they have probably seen a vast amount of opinions also.
I don't believe that it makes them overall smarter than us all. You've missed out allot of names, their just all well known... Doesn't make them smarter than the "Rest".
I believe that i'm pretty smart and well educated, although it may not come across as much because, their may be times were i don't have as much knowledge on a particular Jutsu, or an event that's previously happened, thus getting beaten in the debate, due to me perhaps being misguided or just lack of knowledge. That doesn't make me less intelligent.
The biggest factor is how much you actually spend thinking about Naruto, and how much you are interest. There could be members here who are geniuses, but don't have the same depth of knowledge, due to not seeing multiply opinions, such as old members.
Anyway, point is! You shouldn't pigeon hole people like that.