WWII was even bloodier then WWI.

The obvious difference between current draftee and Napoleon one is that Napoleon set up to conquer other coutries. The peace time draftee is going to have lower mortality.

Napoleon was literally the aggressor.

WWII's civilian/military casualty ratio was way higher than WWI's (~2:1 vs. very very roughly 1:1 or lower), which would affect how the lethality hypothesis affects casualties. When more of the dead are civilians and civilians predominantly die from famine and disease, higher overall death counts in a more-global conflict don't necessarily mean that conflict killed more soldiers per-capita, though some nations definitely suffered higher per-capita military losses due to factors beyond increasing weapon lethality - mostly thinking of Russia there. For instance, furiously crunches Wikipedia numbers in the UK it looks like WWI had a higher proportion of military deaths to population (~2% vs. ~.8%) even though it also suffered significantly more civilian deaths in II, though not enough to outweigh the decrease in military losses as a function of total population.

There might be an argument that increasing weapon lethality can decrease the number of battlefield combatant deaths but also could increase the likelihood of mass civilian atrocity. That said, high-lethality weapons definitely aren't necessary for mass civilian atrocities either.

And sure, I intended a wartime/wartime comparison regarding draftees: even if we go back to WWII as the last real great-power hot war, a French Napoleonic draftee (looking at France as Britain apparently didn't actually conscript in the Napoleonic wars) is significantly more likely to die in battle than a French WWII (or even WWI!) draftee: https://en.wikipedia.org/wiki/Napoleonic_Wars_casualties#cit...