^Yes, I'm aware of the present population disbalance. I'm just saying the origins of the mass approach date from WW2 (and probably all the way to the Napoleonic War) when the Soviets did have a considerable population advantage over Germany. During the Cold War, the Soviets and other Warsaw Pact states practiced extensive conscription which made for large armies. I'm sure the Warsaw Pact always had a higher proportion of the population in arms than the West. Of course, China dwarfs everyone. These days, China's got a real opportunity to have both quantity and quality which would be formidable.
China quantity over quality for me has always been something I suspect to be a myth, even back in the Korean War. Red Army got by with with battle hardened troops with excellent squad level tactics. Think successful guerrilla war. China practices war closer to what its traditional military classics has thought. I don't think its the Chinese strategy to match its opponent on an even chess board. Rather, war is viewed like Go, you are out positioning and out strategizing your opponent with each small step gaining you an upper hand in the long run.
That's why instead of focusing on building better arms, focus on building a better arms industry. Want to build an better arms industry? Find what it takes, better infrastructure, better education, better technological development and so on. When you have a better economy and educated populace, you will have a better arms industry, and when you have a better arms industry, better weapons will come out of it naturally.