First let’s distinguish Dog Brothers (DB) and Dog Brothers Martial Arts (DBMA).
For one we have the Dog Brothers a company of stick fighters (aka “the band of sweaty, smelly, psychopaths with sticks”). These stick fighters meet and fight at their Dog Brother Gathering of the Pack. Everyone who is interested to fight with weapons is welcome, no matter from what martial art he/she comes from.
To become a Dog Brother one has to be admitted into the “Tribe”. To be accepted as a tribe member one has to fight at Gatherings. The first level is “Dog”, this can be achieved after participating in about 3 Gatherings in which the aspirant has fought several times each. If the Council of Elders like the fighter and recognize his/her potential, the odds are that he/she ascend further to “Candidate Dog Brother” and later to “Full Dog Brother”, and gets his/her personal nickname.
DBMA however is a martial arts style founded by Guro “Crafty Dog”. The influence of various martial arts and the experience of countless RCSF fights, led “Crafty Dog” to originate this style in the mid-nineties. More about DBMA → here
It’s possible to train and learn DBMA without fighting at Gatherings. On the other hand it is not necessary to train DBMA in order to fight at a Gathering.