system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Do Stormtroopers have to be "human," or do their heads just have to fit in those helmets?

Either way, is it a cost-saving thing, a "strength through uniformity" thing, or does the Empire/First Order have some kind of racial purity/skull-shape ideology?
gpt
The Empire are a bunch of racists and that ideology permeates all of their military branches.  Pilots, soldiers and officers are almost universally human.  Aliens who go to the academy quickly learn that they aren't welcome there, and those who fight the system and stay through to graduate are quickly shipped off to some backwater planet and never make it past private (or ensign as applicable).

The first order modeled its entire organization based on the Empire, racism included.