In establishing the final format of the analysis ,how you structure your list of hazards depends on a number of factors.

If the analysis supports an organization with an all-hazards focus, it makes sense to list the hazards from most hazardous to least hazardous in one single list, regardless of the general classifications involved.    However, if your organization has separate budgetary allocations for natural, human systems, and conflict hazards, it may make more sense to list hazards from worst to least within those classifications.  And if your doctrine assigns one classification as being the most important, then those hazards sit at the top of the list regardless of their rankings.