Okay, I've been thinking about this for a while and I've never heard anyone mention it, so here I go.
Because you are propelled forward while using the dread venom striker, the ghost swing almost never hits as it appears where your last swing was, meaning the second swing appears behind you.
But when using the wild hunting blade, as far as I can tell from the animation, the second "wolver swing" appears just in-front of the blade, meaning that it hits a monster even if you are being propelled forward.
Is this true? I can't test it because I don't own a wild or non-wild hunting blade myself.
Are you saying that the DVS's movement via strikes is so fast that you leave behind your ghost swings?
Like this:
Swing 1, step forwards for swing 2
Swing 1's ghost strike is currently swinging through you.
Animations aren't anything to go off, BTW (see also: Magnus lines) but since you brought it up, one of the two swings slightly faster than the other, and I can't remember which. Are you reading, Bopp? *hint hint*
If that's true, that's certainly interesting, so thanks for posting it.