I've Made a Video about Anarchism

[Athene]

Why would you automatically assume that any and all power grabs would come from a militia, when presumably virtually everyone in society would be armed? 
Seems to me that militia members wouldn't be any more inclined to long for a reestablishment of strict governance than any other group of yahoos--perhaps even less likely. Actually, I would think that militia members would be more likely to value the core principles of anarchy and value "Muh freedom!" more than anyone else.

The whole Everyone being armed, second-amendment-being-protection-against-organized-tyranny is fundamentally laughable.

Well, I'm happy that you're amused--But that's not what I was actually suggesting though.

I was responding to your specific claim that any and all attempts to re-establish governance or impose tyranny would be limited to militia members. 
What I was suggesting was that such a threat could come from virtually any group of individuals not on board with the notion of anarchism; Including, but not limited to, staunch conservatives, religious fundamentalists, Marxists, ethno-nationalists, ex-military...Hell, even ordinary folks who may have just miss having a Constitution and flag to pledge allegiance to could conceivably attempt to organize and implement their preferred brand of law and order. And that they would undoubtedly be armed--as most anyone living in an anarchic society would be.

I wasn't making the case for anarchist society being a realistic possibility. I was simply musing on a hypothetical scenario in which such a society would already exist.

An armed but relatively untrained and unorganized mob tends to self-eliminate through klutzy fratricide if its arms are called upon. An organized and even partially trained armed organization would be a match for an unorganized and untrained armed mob many times its own size.

So in the anarchic world, a thinking person with a mind for power grab will focus on creating or coopting the only organized armed body in its community.

Your assertion hinges on the assumption that everyone with the mind to make a power grab is a thinking person and that thinking people with the mind to make a grab are immune to overestimating their own strengths and capabilities, though. Neither of which is really the case.

So could a thinking person successfully co-opt a militia of anarchist True Believers and bend them to his/her will of reimposing government tyranny? Uh...Sure, I suppose. Lol
It seems far more likely that they would seek to organize a coalition of like-minded individuals and perhaps enlist the aid of some of those ex-military types I mentioned earlier though.