Why Vampires?
Vampires where once human. So, it is to assume that they do fall back on that behavior in the stress of a fight.
From Khajit and Argonians, I would expect to behave like a wild animal if they are about to be killed. The modder could just add some moves from the werewolves and gargoyles to them.
Otherwise, that would be some kind of additional race-ability.
The whole problem with all talk about how Vampires should be is:
All few years, a new movie (book) with a new kind of Vampire comes out. Then, new movies (and books) do use this kind of Vampire.
If someone tells how vampires should be, that just shows what was the kind of vampire he did experience first. And that just tells to which generation he belongs.
Another aspect is, that the player can become a vampire. But how should his behavior change? In a game where is no button to say bad things to your opponent while fighting, is is for me ok if the other side is also not too talkative.
Otherwise, creating a mod that adds some animal-like grunts to the list of things a vampire would say in a fight should not be that hard, except for the real recording.