Using “brownshirt” for anyone in authority is clearly missing the point entirely. There is a reason the brownshirts were eliminated after the nazis came to power. They were violent gangs of nazi thugs operating outside the law to terrorize opponents. When the nazi party came to power they were not useful or necessary anymore, since now the party could just change the law and perform terror through official institutions.
Please stop using that term unless you're talking specifically about the worshippers of Kali who would strangle and rob travelers in India in the 19th century. It does not mean anything else. It can never mean anything else.