Here is the definition of a straw man argument from Wikipedia:

A straw man is a common form of argument and is an informal fallacy based on giving the impression of refuting an opponent's argument, while actually refuting an argument that was not presented by that opponent.

A problem with calling straw man arguments logical fallacies is that there may be no argument involving critical thinking going on. They may be deliberate attempts to attack an enemy by any means available including lying under a pretense of appearing rational.

Those using such straw man arguments win if they get more votes, power or popular opinion trending in their direction, not by clarifying the differences between opposing positions. These are more ethical failings rather than logical fallacies.

Here is Wikipedia again about the straw man technique used in polemical debate:

This technique has been used throughout history in polemical debate, particularly in arguments about highly charged emotional issues where a fiery "battle" and the defeat of an "enemy" may be more valued than critical thinking or an understanding of both sides of the issue.

Once the arguing ceases to be about critical thinking there is no point labeling what is going on as any kind of logical fallacy. If it were a logical fallacy and those arguing were more concerned with the argument than in attacking an enemy, then a fallacy should be easy to fix or accept, much like a typo or grammatical error.

The question the OP raises is whether a false description of an imaginary group in order to easily argue against that imaginary group is a straw man argument or not. Since there is no real opponent who takes this view, it is hard to call it a logical argument or even a polemical debate.

Such an argument, however, might be a caricature of a straw man argument and labeled a comedy or a form of sarcasm. This assumes the audience listening to such an argument sees an analogy between the bogus argument that is being presented and some real straw man arguments they have heard.

Reference

Wikipedia, "Straw man" https://en.wikipedia.org/wiki/Straw_man