The Maoists used their revolution as a way to exact revenge against the upper classes in China by murdering as many as possible, where the Soviets got their class vengeance by enslaving the upper classes with less outright murder.
It's a little more eggheaded than that, but your description does accurately convey how the scale of death is higher with agrarian communists. The Khmer Rouge were another example of agrarian communism in action.
Most modern communists in the US are Maoist bordering on juche (North Korea), which is why they're scarier than your average Marxist-Leninist or Stalinist.
Edit for specificity, in case anyone cares: in Soviet (Marxist-Leninist) communism, which was more urban and industrial, the idea was that you needed a combined effort of different groups who agree on the same set of ideas and goals. Mao thought the true revolutionaries were the rural peasants while Marx and the Russians thought it was the urban poor who would bring about global communism. Soviet- and European-style communism believed that you need an ideological vanguard, a Popular Front (a coalition or, in the case of weirder stuff like juche, a nigh-priestly caste), to keep everything in order. In Maoism, which was more rural and agrarian, the idea was that revolutionary activity was primary and everything else was secondary. In short: you do the revolution first and
then figure out what it all means and what it's all for. Popular fronts and coalitions are seen as a hindrance: direct action is necessary, planning too much wastes time. That's why Maoists are so much more violent.
One more edit: if anyone wants to learn about juche and North Korea, read Michael Malice. He's a meme, but his stuff about North Korea is not.
