NTs - the theorisers and developers of ideas in and of society; those that propel the best way of living; philosophers and scientists
STs - the doers and the guardians of ideas and theories which are put forward by NTs; politicians, lawyers, doctors and teachers
NFs - those that take care of the spiritual and artistic aspects of life in a society; the inspirational figures; artists and icons
SFs - those that ensure peace, stability and harmony among the individuals in a society; the mediators, social workers, councillors and coaches
This is only a very rough outline - it doesn't purport that any one grouped type is bound to that particular area (we've seen NF politicians, NT lawyers, ST scientists and SF artists), nor does it explain that some individuals are wrecklessly unhealthy and are portrayed here nothing like they are in reality.