I don't see how that's relevant? Sure Russia was an agrarian society. But the Bolsheviks political base were city dwellers, mostly industrial workers. Insofar as the peasants were concerned, the Revolution ended when the landlords fled and government ceased to be. Hurrah! The moment the Bolsheviks started requisitioning grain to feed the cities, peasant support for the Bolsheviks collapsed (not that it was ever strong. Peasants supported the SRs who were agrarian socialists but weren't Marxists per say. Russian Populism is kind of weird). A lot of Bolshevik energy was spent into the 1930s breaking the peasantry. The campaigns against the Kulaks. The destruction of the SRs. The crushing of the Tambov Rebellion. Hell Collectivisation itself. All were about destroying the peasantry as a force.
Same with China. The CPC until 1927 was focused on industrial workers. Following the purge, the CPC was forced to reevaluate its strategy. But it still took them almost a decade to settle on a strategy that could win them mass peasant support, Nevermind the fact that the CPC itself took that long to even accept that it was neccesary to do so. Even the mere fact that they had a strategy didn't translate into much peasant support. Sure they had areas where they could shelter and enjoyed popular support. But those were areas they chose as the ones most likely to be support them. Outside of those peasant support for the Communists was weak at best. It took the GMD wrecking the economy and losing the Civil War to gain peasant support. Spain might be a counter-example. I don't know a huge amount about the PCE.
But as a general rule, Communists tended not to rely on the peasantry because it wasn't a revolutionary class in the Marxist sense. As Lenin put it: The peasantry wants land and freedom.... [Land] means reckoning, not on a compromise between the peasantry and the landlords, but on abolition of landed estates... “Full freedom” means election of officials and other office-holders who administer public and state affairs. “Full freedom” means the complete abolition of a state administration that is not wholly and exclusively responsible to the people, that is not elected by, accountable to, and subject to recall by, the people. (Read: people as peasants because that's how the peasants read it). The problem for Lenin is that once the peasants had this, and it's quite a simple list of demands, they weren't prepared to support anything more. Peasants were revolutionary until they got what they wanted and then they became conservative - intent on protecting it.
Given the above, it's quite possible that the Communists lack a popular base. The peasants won. Fighting messes with things. And that number of troops are going to be requisitioning alarming amounts of food. There's like 300,000 Communist troops. That's, ah, like 70% of OTL Oxacana's population in 1930. A hard turn left also brings with it more friction across a range of things. Do the Communists shoot colloborators? How does one define colloboration? Does it include members of the elected commune governments that must pepper the south? How about priests? The Church signed onto the Treaty ending the war. It raises a lot of questions.
