I think you can equally rank them but communism is the more dangerous ideology because it's been gaining traction in parts of the world while national socialistism is universally shunned
Thank god it is lmao
Main reason communism killed so many people is because countries that had not undergone an industrial revolution yet, which is an incredibly important part of sustainable communism. Thus, the only way for Stalin and the like to catch up with the world was to force rapid industrialization. It worked substantially well for the economy, but the people, on the other hand, suffered. Luckily, most countries have undergone an industrial revolution by now.