@Mojo Well. Im a year late with this. First of all, the vampires in this story are western vampires with easterner's brains
Basically, western vampires are the original while eastern vampires (jiangshi) are an "imported concept crossed with zombies". While vampires are also kind of "undead", they are also not quite "dead" -dead. Those that get their blood sucked become vampires more like an infectious transformation disease.
On the other hand the Qi/lifeforce sucking jiangshi (doesn't suck souls) are effectively dead and move through instinct more like Resident Evil zombies. The reason they hop with their hands up is because of rigor mortis "freezing their limbs". Basically, they can't bend their limbs so they resort to hopping with their hands up (for balance). In other words, they are more zombies less vampires.
Speaking of which, don't look at Qiqi from Genshin Impact for reference. The only thing jiangshi about her is her outfit.