You're arguing that some aspects of Hitler's National Socialism don't match Fidel Castro's Marxism-Leninism, while purposely ignoring all similarities, common to any totalitarian and repressive regime.
Castro's long list of political executions are well documented. We may agree that Nazi death camps have a scale of their own, but this is no reason to turn a blind eye to the oppressive and persecutory nature of Fidel Castro's regime.