Have you done Newbie 1 and 2? They are the "entrance" point to the Nihongo Dojo Series. Its like Newbie 1 -> Newbie 2 -> Beginner 4 -> Beginner 5 ...
So i think you should try Newbie 1 and 2 and if the are to easy for you got to Beginner 4.
I have done them all in order up to this point. I did Newbie 1 and 2 and 3 and 4, and now I am on 5. But 5 feels like going back to almost day one and starting from there instead of building off of Nihongo Dojo.
what's why i'm confused as to where to go to get to the next level,not that i'm opposed to review, but 50 lessons of review seems a little excessive.