There is an excellent Allianz report on family structures available at this link. Although this is based on US data you may consider it a leading indicator of the family changes taking place in New Zealand. Another line of inquiry is to contrast the types of families described in the report with your last couple of dozen cases - or in the case of insurers to consider the people you work with and your family and friends.
The real insight is to understand the different purchase motivations and use those to help solve the difference sets of insurance requirements each family will have. At least a general understanding of estate planning or a close relationship with a good family lawyer is required to provide effective advice on many of these issues.