double throw,double swing

[Guest]

When a barb uses 'double swing' or 'double throw', do the mods (including the damage) of each weapon stack? For instance, do the mod '-25 % to target's defense' of each weapon stack to make -50% ?
The mods should stack because the target is hit by the two weapons at the same time,unlike frenzy for instance for which case,the mods of the two weapons don't stack.

~Abramelin~