No, corps are fine. They are very useful and even essential in some cases. But they have power now, more than the people who work for the corps or the people who buy from the corps. That should be reversed. So let the corps live, but castrate them.
This reminds me of "day of the trifids" where the world is "invaded" by evil, aggressive,s walking plants. Not very frightening on its own, but at the same time a meteor flew over earth that blinded most of humanity leaving only a hand full sighted. That changes the premise quite a bit.
I don't think these are technically nazis. Nazis have a political purpose for which they do the things they do. These folks don't have a purpose or an agenda besides murderlust en powerhunger. Nazis are evil as a byproduct, a side hustle. These folks are evil as their core business.
The last one, with the bark squirts, is the best