Meh, keeps the Thunder Boys off at least......
Dark seems more of E4 thing, although Bugsy might want to argue that point, as well as many fighting type gymleaders.
They should maybe get one of each and every type, and add a new one just to keep it even, or they could be 12 gyms and the E4 and Champion all using different types.
That gets me thinking to when Gary in the first season said he got 10 badges, yet lost to Giovanni and Sabrina, that could happen in future games, and it would make it more even