"an-com ideology would advocate individual freedom while aboloshing State hierarchical institutions"

Communism, socialism, any similiar ideology cannot advocate individual freedom, they just cant. The basic principal of these ideologies is that the people give up their rights and freedoms as indivudals, in order to gain democratic control of production as a collective.

"I think conflating hierarchy with government is a mistake here. "

I disagree. The government is a form of hierarchy. It forces itself to the top of society, and then uses aggression in order to tell people how to live. However, hierarchy can also be voluntary so I see your point. Relating to communism though, voluntarism is irrelevant.