Thinking about their organization, hierarchy, and network (not really thinking so much about gangs like "the orphans") but more like larger groups (not naming names). A SHTF would definitely be interesting.
Are you thinking not?
I think the organization and structure might help in some way but that does not make them more prepared than others. Much of that structure revolves around, and functions in an orderly society that actually protects their activity. Couple that with the fact that the "brotherhood" angle is often overstated and these gangs are rife with backstabbings and betrayals...especially when times get tough.
They will require the same skills, abilities, supplies, and mindset that everyone else will need. Being in a gang doesn't fix any of that.