Armor debuff does not stack (?) Rogue skills

[resurrected]

So today i was bored and tried to test some rogue skills. I unlocked armor reduction in shadow Pierce and in aimed. Took a while when i tested and found out that it don't stack. When i shot aimed and then Sp and it apply armor reduction then -15% from aimed is gone and in place comes -10%. Why it don't stack while it should ? I heard that max reduction is -35% that we can stack and here -25% not work... SP is bugged?

[Ydqm]

The highest one works, they don't stack. If you had the venom set with 200% speed and a pet that has 10% speed, you'll only get 200% speed.

[resurrected]

The highest one works, they don't stack. If you had the venom set with 200% speed and a pet that has 10% speed, you'll only get 200% speed.
So sp and aimed wont stack ? Oh :/ got it now thanks