Left anarchists don't consider anarcho-capitalism as real anarchism because capitalism allows hierarchies. The main reason why hierarchies are considered bad is that it hurts the autonomy of individual. So left anarchists maintain that when there's hierarchy, individuals can't be autonomous. But I don't think this is the case. There can be situations where there's no hierarchy but also no autonomy and there's hierarchy and also autonomy. Consider following examples:

In a democratically governed factory (a factory which workers own and operate democratically) the workers will decide what to produce, some say they should produce Karl Marx tshirts and some say Murray Rothbard tshirts. They vote and majority of the workers votes for Murray Rothbard tshirts and this is it. Now, although there was no hierarchy and it was a democratical process the minority's wants are ignored. Can we say that if the minority has no say in this process they actually have no autonomy? If yes, doesn't this also mean non-propertian anarchy doesn't protect autonomy? Isn't the tyranny of majority contradict your nonhierarchal and pro-autonomy view?

Objection: But other workers had a say in the process. They voted. Just because they are in the minority doesn't mean their autonomy violeted.

Response: Vote right isn't same as being autonomous. You can have a right to vote but if you're a minority and know that your vote won't change anything your ideas doesn't actually have any importance. This still violetes your autonomy because you will be ignored no matter what you think as long as you're not with the majority. I live in Turkey and am an atheist, I don't want Islamists to govern me, I do have a right to vote but since I'm in a minority my vote doesn't mean anything, I still have to (legally) obey the Erdoğan's Islamic rules. I think it's safe to say my autonomy isn't respected. Or just because I have a right to vote I'm fully autonomous? If so, what is the difference between the scenario of the democratic factory and my political vote.

Or there can be hierarchy and autonomy:

Suppose that me and my friends decided it would be great if we establish an amateur soccer club. We established the club and found a coach for ourselves. Although there's a hierarchy between the coach and us, it's something we all wanted. Can you say our autonomy are violeted? I don't think so. Doesn't this prove that there can be instances where there's also hierarchy and autonomy?

Also, imho, in an anarcho-capitalist system there's a room for full autonomy: Being self-employed (or petit bourgeois)

My questions are:

Why hierarchy is so important? Can't there be voluntary hierarchies? If you're okay with (voluntary) hierarchies why do you say anarcho-capitalism isn't anarchism? If you're against all hierarchies how will you escape from the tyranny of majority (such as my example)? If you can't doesn't this mean left anarchism is also contradictory and not real anarchy?