Scenario: Imagine the world suffered a catastrophic event like a meteor strike, plague or nuclear war, which destroyed most human life and all of the developments of the past century. A mixed group (age, gender, ethnicity, religion) of a few hundred lucky people has survived (it's helpful to agree where - anywhere - because location will influence some aspects of the approach to the question).

Question: If this group is to thrive and develop, what initial leadership structure would you suggest, stating 6-12 key roles?