Full Armor & Damage Reduction Analysis.
http://s10.postimg.org/g219ph0vt/Armor_Analysis.jpg
As part of supplementary tests, I would also like to confirm that neither the enemy's HP/armor nor its damage are scaling higher depending on if there is a warrior in party or not. With everyone in party at the same level, the mobs' difficulty only depends on the number of players in the instance, not the classes. You're welcome, warriors!
There might be another topic coming containing the exact percentages of how mob's damage, armor and HP are scaling as more players join the party. For now, as a general guideline, mobs and bosses seem to scale smoother for three players comparing to four, purely from a statistical point of view.
Bonus info: The damage reduction from both Nekro's & Scorch's shield is 40%. The difference is that Nekro's absorbs much more HP before it breaks.
Hope this helps. :)
Full Armor & Damage Reduction Analysis.
This time, Rogues should get hit, after all it' s about Rogue's armor loss effect :). Madnex chose a specific mob because it gave constant damage, so there was no need to average the data. Best use Weapons without proc. Have fun!