The soldiers complain that they have only just learned they will be sent to the front and haven’t even seen a rifle during the two weeks they’ve been training.

Right, Russian soldier. If you have been given rifles you may have used those to have a say if you went to the front, so the commanders solved that by not giving you any. In fact, you won't even need them for your assault. You'll be used in probing attacks for commanders to determine where Ukrainian defenders show resistance where you'll very likely be picked off long before you get in firing range. Why waste given you a rifle when you're just going to drop it in the mud without ever firing it when a drone finds you and does you in?