Twice the land mass but where the PRC has 1.4 Billion people the Russian population is only about 146 million. Much of Russia is empty space Pock marked with abandoned Soviet “ghost cities” single industry centered population centers where in all was built to cater to that sole industry until the Russian Economic collapse and fall of the Soviet state resulted in abandoning.
Hundreds of Prypiat like cities home only to fading memories lost back to nature.
if we look China and India both have far more soldiers than Russia in their ground forces.
India also has a huge population roughly equal to the Chinese.
I think eventually China & India will have around 500k soldiers serving on their land forces as training and equipment become similar level as US army's... aka not cheap.
I agree that there will come a decline for the PLA numbers. The main mechanism being an aging population with limited growth resulting in declining ability to serve. On a smaller scale this is more or less what we see in Japan. In the PRC the one child policy accelerated a population decline that occurs with a high standard of living. IE less demand for children as said children live longer creating the “Nuclear family” model.
The Indian population is harder to figure on. The dramatic population economic differences mean that you have a dramatically poor poverty line with a modern growing urban center attached at the hip.
The rural areas population encuraged to have lots of children in hope that some will survive to adulthood due to a high death rate by low living standards. Sits right next to a thriving urban population with modernization of medical technology that allows more children to survive into becoming functional adults.
Without an artificial population control like the one child policy the Indian population seems to have no limits. This means that the only break on a massive land Army is the economic constraints of The Indian state.