Your proposal is interesting. One thing is that there is a very simple measure of success in AA, which is how long has a person refrained from drinking, but there's no simple measure of success with mental illness. I think this is why AA can be so successful with their mentor program but you don't see the same interest in the mental health field. In fact many group therapy leaders urge people to refrain from interacting outside of sessions. I am not sure why that is.