Well, I actually think that could be pretty close to the real game actually.
They officially presented two classes for the Greenskins: Goblin Shaman and Black Ork. The one fighting the dwarf is a Black Ork.
One of the main characteristics of the Black Ork class is supposed to be dirty fighting tactics using parts of his body and spikes and stuff on armour ect.
So the way the Chaos warrior fights might actually be in game, with the kicking in the wound and all.
Mythic Entertainment - Warhammer Online