I agree with all the other comments regarding the choice of the word hierarchy. This word has a very specific meaning (pointed out by Susan B. up here) and it has been used with other meanings that I find incorrect. You can’t just use some bold statements like the title of this article with this underlying misconception.
I want to add the fact that the word hierarchy has also a not indifferent weight in its socio-political sense. Especially among the libertarians the word evokes a very bad feeling and is one of the main conceptual adversaries an anarchist should fight. So telling that organizazions with no hierarchy “are not a thing” put you in quite a bad light. I understand that the point is another, but the bad word choice is obvious. You keep saying that you’re not attached to the word hierarchy, but you used it, and words are important.
I suggest you to set aside this article and rephrase the whole thing in the light of this misinterpretation: the new article would be more pleasant and agreeable free of the inaccuracies.