Armor Defense how this stat works

[EaglePhoenix]

Overall I dont understand what is better for bonus on equipment.
So I decide to make a test but for sure Im doing somewhere mistakle:
I put all Sedo set on me and bought 3x Darkness tasset : First clear (HP reg. bonus) , Second Darkness tasset 2% armor def and Third 2% p.def .
Me p.def with clear dark tasset was 423 ,
with 2% armor def: 427 (2% from 423 ---> 8.46)
with 2% p.def 431 ( it works good )

I know armor defense should take 2 % from our currently armor but then
armor def < p.def is always better. So for what and how is Armor Defense bonus stat works?
Thanks guys for help!

For when you plus your armour, your armour stats grow and so thus the AD received.



I think.