I actually think that is wrong in the early levels, Fozzie.
24 armour absorbs 18 damage (when hit in the torso)
36 armour absorbs 24 damage
Unless the incoming hit is doing pure piercing damage (ie Honing prefix, or a skill, etc), then the incoming piercing damage is quite minimal early on, and resisting 7% of "very little" is quite a bit less impressive than upping your armour by 50%.
Melee toons should focus on armour rating for Act 1 Normal... barring any awesome affixes. Playing Xmax or ticking some of the remove broken/white/yellow boxes in Defiler can change that advice, but for vanilla TQIT, I focus on armour first in A1N.