>The discussions I've seen point more towards Legalism, a Chinese theory of governance that's similar to fascism.

I agree, but "legalism" has its own meaning in Western philosophy, so "fascism" is the more appropriate terminology to avoid confusion:

https://en.wikipedia.org/wiki/Legalism_(Western_philosophy)

>Especially because China has a long, cultural history with Legalism

This is something that most people won't know without a detailed study of Chinese history. Legalism in China won the day against Confucianism a long time ago in 221 BC, when the First Emperor of China came to power, and has never quite lost its place in Chinese political thought since.

Hmm, perhaps the best approach is to use the official translated word from Chinese: Fajia, to represent the concept and minimize confusion.

Ex: We could translate "Samurai" into "Knight", except a Samurai code of feudalism was completely different than a Knight's code of feudalism (even if both were forms of feudalism). There are also major differences in how the aristocracy worked between Japan and Europe. At some point, its best to just stick with the native tongue.

>perhaps the best approach is to use the official translated word from Chinese

Sadly, the "best approach" has a good track record of being the approach that is usually not taken.