Brown belt...yep. Same thing in karate. Know just enough skill to have some effect but not fully controlled, and are usually young and enthusiastic enough to apply that as vigorously as possible. I hate sparring brown belts, lol.
I'm guessing brown belt is some where between 2nd-1st kyu.(we use only white belt until yudansha.)
The shidoin I had talked to also had the same opinion of new black belts.
He feels that people are confident in their ability years before they become competent in their abilities.