Sigil: City of Doors

On the wikia, it states the following:
"Archonic Armor: A Trumpet ArchonÂ’s skin grows resistant to blows, gaining a +1 (stacking) bonus to natural armor at level 1, and a +1 (non-stacking) natural armor bonus at each successive level."
What's the point of getting +1 ac per level if it doesn't stack with anything?
Am I missing something here? Because that just sounds pointless.

I mean: 9 X 1 non-stacking AC = 1 ac total, right?

It stacks with itself, but it doesn't stack with natural armor boosts from spells or items.

Alright. Thanks for clearing that up.

Lol...