That’s like trying to paint Karl Marx as “Jewish” too, after his father had converted to Lutheranism and the man himself having been an atheist who wrote antisemitic treatises.
A score of 3 on the second link seems to put Fidel and Raul very far away from being of the tribe, so ethnically (and certainly ideologically) they are way less Jewish than Karl, who scores 11 on the same site.
A Jew is Jew no matter how far away from Torah they run.