It's just me, but I have trouble with using Castro in the same breath as Hitler, Mao, and Stalin.
Understand. He should have been a baseball player.
Maybe just a matter of scale, but his designs on Latin America and Africa were big, and the suffering and damage he did to the cause of freedom is still felt to this day.
Substitute your favorite despot.
Why would you have any trouble doing that? The only unfortunate difference between the 4, is that only three of them are currently roasting in hell. Stay tuned, however, as they soon will share one more similarity.
Okay, it's just you. We'll go on making the analogy.