You do understand that Guards weren't universally the best troops, nor were Rifles universally the worst. In real life, a Conscript could be a great shot, all people are equally predisposed to dying on the battlefield despite their Elite status. I'm a great shot and I have never been to war. I'm pretty sure that most Americans were great shots then because many went (and as I do till this day) hunting, not as a sport but as a means to survive. The Common Soviet was not a marksman unless he gained that skill on a battlefield.Being outnumbered means little in a war were both sides possess MGs, and other modern weaponry that could mow lines of infantry in half. By the end of the war, most Conscripts were part of Strelky and Guard regiments because by then the tide had turned and the Soviets had the equipment and time to give them proper training (which by this point many didn't need)
You do understand that Guards weren't universally the best troops, nor were Rifles universally the worst. In real life, a Conscript could be a great shot,