This aspect of “mobility” is perhaps forgotten as an element in WWII, but it was a “tactic” used more often than tank-supported advance in the Soviet armies:
Even (or especially) in open field advances (the WWI precursor of the Human Wave assault)
But for reasons of politics (it would have elicited strong resistance from “outer circle”, non-Whampoa commanders) drastic cutback (to improve quality, starting with diet) was never implemented. By war’s end, many “National Army” battalions looked as if they had been through the Bataan Death March. Paper strength (important when seeking American aid) never diminished, though of course effective strength did.
On the other side of the political coin, 8th Route Army MANPOWER SIZE (as opposed to ordnance) kept growing, though with one major interruption (the 100 Regiments Offensive). Having arrived in the Special Area in 1936 with at most 25,00 to 30,000 weapons bearing footsoldiers, it had reached a (scheduled) size of 570,000 (Peattie, 253) by early 1940; after a dip of (reported) 100,000 in 1940 it seems to have flattened out at 470,000 (V, 237), regular armies are believed to have reexpanded to 900,000 (supported by 2-3 million “local forces”) by War’s end. Though of these only a fraction were billeted/based in the “Special Area”: Vladimirov estimates the “garrison” of that latter triprovincial base area (213) at UNDER 100,000, with the remainder (800,000) in the Japanese rear. Nonetheless, a 4-fold increase, achieved by adding existing units from the OUTSIDE: there was no significant recruitment from inside the SA. (Though there WERE enlistment campaigns….)