The Irish wolf hound mix that goes camping with us has never showed any sign of fear even when we saw a pair of wolves. Of course his people where right there.
I think its like people. Some people are afraid of spiders and snakes and some are afraid of heights. I believe that there are dogs that are afraid of people and some that are afraid of other dogs and some that are afraid of wolves.
I don't think there is a dog out there that could take on a pair of wolves by its self. While there are dogs that are a bit bigger than wolves, the wolves typically work very well together. Wolves regularly take elk here in Idaho and if you have ever seen an elk up close they are much bigger than even mule deer. Granted they usually do not go after the big trophy bulls but if that was all they could find they are more than capable of taking those bulls (in my opinion).
Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull.
all 23 of my guns are 45/70 govt 357 mag, 22 or 12 ga... I believe in keeping it simple