I don't know what kind of setup you have for clubs where you are, in England. Here we have the Doberman Pinscher Club of America, which is the parent club for the breed in this country. It writes and owns the doberman standard used in the AKC conformation ring. Benefits to DPCA membership would be getting to vote on standard changes, being able to futurity nominate your litters.
We also have DPCA chapter clubs which exist under the DPCA umbrella. These are smaller clubs spread around the country. They put on dog shows, do some public education. Some chapter clubs also are involved in rescue, although not all.
I belong to the DPCA, but in 20 years of owning dobermans and being active in this breed, have never joined a chapter club, due to lack of interest. Too much squabbling, too many situations where one faction literally takes over a club.