Lemmy.ml taught me that there's no difference between a Tankie, and Evangelical, or a Sovereign Citizen. All have discovered the magical words that keep them from being responsible for their own behavior.
There are some differences, but also the similarity you mentioned.
One thing worthy to note though imo, tankies are evangelical. They are literally evangelists, literally evangelising their politics. Evangelism isn't limited to christianity. Definition #2 of evangelism is "militant or crusading zeal," they clearly fit that since they want to line up "only landlords I swearsies" up against a wall and won't shut the ever loving fuck up about it.
To be fair I'm a linux evangelist, so I can't talk too much shit, but at least linux is not "shooting people in the head" so I think I'm a little better.
If you trace the unbroken chain of bored trolls back from .ml you see the path goes through a TON of social media groups that have died out. You can go all the way back to CTH on Reddit and even earlier to some groups from Digg.
Makes it hella easy to clean your feed when the shit congregates and isolates like that.