WE Armor piercing skills/tactics and Weaponskill/armor pen.

[Aezron]

Hello,
I've been wondering how my WE:s armor penetration from Weaponskill stacks (or not) with my WE armor piercing and armor ignoring skills. Mainly these two tactics/skills:
Bleeding Edge (armor penetration increased by 50% after Frenzy)
Elixir of Insane Power (attacks ignore 50% of armor)

Say I have Weaponskill corresponding to 20% armor penetration.
My target has 1000 armor.

Normal attack leads to 1000*(20%) penetration = 200 armor penetrated, i.e. 800 "effective armor" left.

Now how does it work with BE? I think one of these two scenarios, but maybe not? And if that is so, which one is it?
Attack with BE leads to 1000*(20%*1.5) = 300 armor penetrated, i.e. 700 "effective" armor left.
Attack with BE leads to 1000*(20%+50%) = 700 armor penetrated, i.e. 300 "effective" armor left.

And now with EoIP
Attack with EoIP leads to 1000*0.5*(20%) = 500*(20%) = 100 armor penetrated, 400 "effective armor" left (-500 from EoIP and -100 from armor pen.)

I guess it would be the same if armor pen. was calculated before armor ignore.. but could affect certain situations that e.g. negate armor pen:
Attack with EoIP leads to 1000*(20%) = 200, 1000-200=800, 800*0.5(EoIP)=400. 400 "effective armor" left (-200 from armor pen and -400 from EoIP)

Anyone know how it works?

[Elemint]

They're both multiplicative and don't stack with each other, so both result in 60% arpen in your case

[Aezron]

Oh so it's the same effect, even though the wording is different. Thanks!

[SuperStar]

They're both multiplicative and don't stack with each other, so both result in 60% arpen in your case

Can you tell me the how it 60%?

[Elemint]

Can you tell me the how it 60%?

Arpen from WL tactic, mara tactic, WE/WH tactic, WE/WH ability (and perhaps SW tactic, but i don't know for sure) stacks multiplicatively with arpen gained from WS. He said he had 20% arpen from WS so with the ability/tactic he is reducing 100% of attackers armor for 20% by WS (now 100 * 0.8 = 80% armor) and after that by another 50% of the left over armor by the ability/tactic ( 80 * 0.5 = 40% armor). If his target is mitigating with only 40% of his total armor this means he has 60% arpen.

[SuperStar]

Thank you very much.
So basicly this tactic is less worth and worth with more armor pen from ws.