Again, this only applies if we blindly use the cold war association that communism is a left wing ideal, without actually looking at the policy of the people.

The reality is that communism as a movement spans a wide political range, and both Stalin and Pol Pot had diverged significantly from any form of leftist Marxism in their hunt for power.

Even stalinist supporters decry Pol Pot https://msuweb.montclair.edu/~furrg/pol/khmerrouge.html

Looking at simple party names is a red herring at best. It's best to look at the policy choices of the dictators in question.