As Karnstein fled through the forest, he heard the footsteps of the pursuers slowly lessen in ferocity. The biggest danger the vampires could face was the [Regeneration Blocker] provided by the Shadow Hunter System. The fact that the strength of the ability stacked with nearby people with the same ability meant that with enough people, you could block the regeneration of even the strongest vampires.
Without their regeneration, they were just vulnerable to attacks as humans were, especially to projectiles. This method could likely take down Marquee or even some of the weaker Duke-ranked vampires.
However, this strategy came at a cost. There were only so many humans on the planet with the [Regeneration Blocker] ability, not only that but the ability doesn't actually weaken the vampires in any way. If you couldn't land a hit on the vampire in the first place, there was no difference whether you had [Regeneration Blocker] or not.