Hmm?
The average level 2 enemy can bypass 40 armor better than the average level 1 enemy. That's basic level mechanics. I mean, if a level 1 and a level 2 enemy had the same amount of strength, health, magic, etc, the PC would never face a challenge after a few levels.
if a level 1 and a level 2 enemy had the same amount of strength, health, magic, etc what would be the point of having a level 1 and a level 2 enemy?
I understood the description as your armour got weaker as you levelled up, simply because you levelled up, meaning that a level 1 enemy would have an easier time hurting you (not the same as killing you, as you presumably have more hp now) when you are level 5 than when you were level 2, hence my "level scaling" comment.