So, recently Twilight answered a long as hell question about the govermental operations of Equestria., It shws a cross section of operations in the world. Now, I can understand the Pegasi's roles, nature and weather control as well as external relations makes sense considering their wings, and Unicorns controlling magic makes sense. But why do Earth ponies work with Justice? Considering most Earth ponies seem to work on a rural basis I would assume Trade to be their strong point but no.
Because pegesi and unicorns looking to work in law enforcement would usually join the Equestrian Guard, where they’re highly valued, not local justice systems.
