Elite NPC Damage is Way Off (Plausible Evidence)

In that case he would do way too much dmg, but you forget that

a) Armor damage reduction has an attacker level component
b) He still uses a shield

You can expect him to get close to the 75% reduction cap. If he got hit for 35, we’re talking up to 140 against 0 armor. The lvl 19 druid from the video has 1808 armor, which should be like 45% DR on that level (just an educated guess), and he takes 45-80 dmg, which seems right. (140*0.55 = 77)

tl;dr: from video evidence in this thread the dmg is correct.