What somebody says != what somebody does.

If somebody says something nice and does nothing, that's good.

If at the same time somebody does something bad, that's bad.

That does not remove the evaluation (nice or bad) of the speech alone.

Saying "I am against this thing that is objectively despicable" is GOOD.

So, saying to be anti fascist is good.

Saying to be anti fascist and doing fascist things is bad.

I don't know how much more obvious things I am supposed to explain...

I guess there is no limit to it.

You are assigning this magical reality and then getting mad about it.

Anti-fascists are not concerned with the magical weight of this in-group designation. They are concerned with all things non-fascist.

And you are factually wrong.

You are probably thinking about the Communist factions among the Republican forces opposed to Franco.

ALL of the Republican factions were opposed to Franco and to fascism, not only the Communists.

And, besides, nobody was calling themselves "antifa" at that time, because that was damn obvious that if you were in the Resistance, you were opposed to that despicable tyrant. But they were absolutely anti fascists, all of them and not only the Communists.