This is an interesting question. The wolves are presented as hungry, man-eating animals who love to prey on the weak and injured, and therefore we could say that this story does contribute to myths and fairy tales where the wolf is constantly given the role of the antagonist or the evil, three-little-pig-eating and Grandmother-chomping wolf. However, I think such a view of the wolves in this story would be rather superficial. We need to understand what Saki is actually trying to achieve through casting the wolves in the way that he does and what he is saying about nature and fate.
Firstly, Saki creates two distinct conflicts in this story: the conflict between two men and the conflict between man and nature. Clearly, the latter is harder to resolve and Saki seems to be suggesting that actually it is easier to settle feuds like the one that is featured in the story than it is to resolve the conflict between man and nature because nature contains elements such as wild animals that cannot be controlled.
Secondly, it is important to realise how this story shows what Saki feels about fate. Clearly, for Saki, fate is a factor that is beyond human control and unable to be manipulated or managed. Ulrich's "idiotic chattering laugh" sees the immense irony in this as he is able to see that the approaching sounds are not men but actually wolves. Their fate is out of their hands.
So, whilst I suppose Saki could have exchanged the wolves for a bunch of rabid carnivorous squirrels, we have to accept that wolves probably work best in this situation. Whilst recognising that it does perhaps build on stereotypes, we need to be aware of how they function in this short story.