Armor is PHYSICAL resistence only. Hence “all resistence” also implies physical.
From all the guides I understodd that the importance of defense is
- Vitality is always first
- For Strengh/Dexterity classes: Vitality > All-Resistance > Armor > Single Element resistance
- For Intelligence classes: Vitality > Armor > All-Resistance > Single Element resistance
Also, as secondary resistence you want physical resistence on your gear for Intelligence classes, and “any element” resistance for STR/DEX classes.
Plus, sometimes you also want %life. I.e. for the wizard’s shields which give you protection for % of your life.