Oddly enough, although both of my parents were actively alcoholic through most of our childhood, none of us four siblings took on the classic roles 100%. There was no one 'hero', and we were all more active as 'enablers' than anything else.
My now deceased (cancer) brother and I took on the roles, respectively, of 'scapegoat' and 'lost child' to a 60%-70% degree, but he was successful socially and, later, in business. I managed to get a graduate degree from a good school, but have since drifted a bit in careers. And the lack of any significant intimate relationship outside of family, ever, confirms a big percentage of the 'lost' role.
I would speculate that we all predominantly took on the role of 'detente-keepers', sort of a super-enabler. All four of us never argued or yelled at each other - we settled problems quickly without going to our parents. Sound's like a parent's dream, huh?!! We all knew any conflict was just fuel for a future withering drink-fueled attack from my father. Nothing could make one feel corrupt and to be a waste of the universe's atoms like the verbal machete attacks of my father. To take the Cold War analogy further, we lived under MADness (as in mutual assured destruction).
My two remaining siblings and myself have a strong tendency to avoid conflict and emotionally difficult situations. It is just hard to turn off that Distant Early Warning system that sends one quickly to the emotional bomb shelter (ok, ok that is the last cold war thing I will use). This has really impacted each of us in our careers, as no one has really had much of any success. But, having read the trials of many of the people here, it is the truth that we have done fairly well given the so-called upbringing we had. I am not angry at my deceased parents anymore, as it is clear that they did the best they could with a really limited set of tools and years of addiction.