FAQ poisoned special rules

Maybe I dont get it but I am confused, with the wording of several poisend wepons.
E.g. Shaimeshi blade:
It keeps the "poisoned Weapon" rules but changes the second sentence:
"Each time an attack is made with this weapon against a unit
without the Vehicle or Titanic keyword, it wounds the target on
a wound roll of 2+, instead of 4+"

so do I wound a vehicle on a 4+ or 6+ (becoause of the Poisoned weapon rule)?

It'll wound a vehicle on 6+.

It wounds a vehicle on a 6, just like a normal Poisoned weapon.

Well, thanks.

but why don't change the wording to "Each time an attack is made with this weapon against a unit
without the Vehicle or Titanic keyword, it wounds the target on
a wound roll of 2+, instead of 6+"

Maybe it will be for some future rules.

Because the default is that poisoned weapons wound units without the Vehicle or Titanic keywords on a 4+.

The "instead" is acting on how poison weapons behave for non-vehicles/titanics.

Basically, regular poisoned weapons say something like "This weapon wounds units without the Vehicle or Titanic keywords on a 4+. It wounds Vehicles and Titanic keyword units on a 6+"

The Shaimeshi Blade and Agonisers are just like regular poisoned weapons, but "instead" of wounding infantry on a 4+, they wound on a 2+.

They way they have worded it is, in fact, grammatically correct (while my own post is a grammatical mess!)

Ok, I think I got it.