I have heard the word 'patriarchy' used to denote all forms of oppression and inequality in society.
Not just male subjugation of females, but also males subjugation / oppression of other males, based on power differentials and linked to 'macho' culture.
But surely this is an over-reach, an over-use of the word?
It is implicit in the word that it is about males vs females, as shown by contrasting it with the word 'matriarchy'.
If you are talking about men oppressing other men, you need a different word. Something to do with men's tendency towards establishing hierarches amongst themselves and bullying of any 'lesser' man.
Patriarchy is not a catch-all word describing all forms of oppression and inequality. It has a specific meaning that should not be lost.