The "2 rifles for one man" thing is mostly BS iirc, however the lack of cartridges and especially heavy weapons (MGs, AT guns, mortars etc) is correct especially at Stalingrad, not so much because they didn't have enough of them in the first place, but because ferryiong equipment accross teh Volga while the Stukas were assraping them was difficult.

The human waves thing is absolutely true however, although by the end of 1942 the red Army was finally getting somewhat modern, and the commissars and NKVD were losing Stalin's favor, so the actual officers couls start doing their job normally without getting shot by some jewish manlet commissar.