I think we are kind of arguing past each other. I (mis)understood your comment on “disposable” meaning cannon fodder troops while keeping your best and brightest out of the fight.
That said, you are mistaken about their surplus military aged population. Russia has just under 150,000,000 people and fewer than 45,000,000 are military aged males. Of course, Ukraine has a mere 35,000,000 people total so the man-to-man comparison is off the scale…basically Russia can easily afford to bleed the Ukraine to death and lose significant numbers of soldiers. Still, the 1/100 number is off…some 700,000 Russians have been killed or wounded (no longer battlefield effective) meaning Russia has lost 2% of their military age population - not an easy number to make up in a nation already in population decline.
This isn’t 1941…Then Russia had nearly 180,000,000 people (most of them military aged) facing a Nazi “empire” that could count on fewer than 90,000,000 not considering the burden of a two front war and the coming avalanche of U.S. military aid (that frankly kept Russia alive). Today NATO can fall back on a combined population of some 390,000,000 and that doesn’t even count the roughly 330,000,000 in the U.S. So, war is, in fact, that simple and Russia is terrified because they can count. The only complex side here is nuclear weapons and the question of Russia would rather go out kicking, or screaming. As for the rest, I completely agree. The U.S. and Europe have, quite frankly, kept the Ukraine in this fight.