My vote is on the wolf.
Back around 1970-71?. We put two good coyote hounds on a fresh coyote track. One of the hounds, a Black & Tan weighed 110 lbs, tough as nails. The other hound was a Walker hound, another tough hound. Both were experienced coyote hounds. I'd est the Walker was around 60 lbs or so. Both were males & both were relentless with long endurance.
Well, this coyote track apparently crossed a lone wolf track. So the hounds took after the wolf. They caught the wolf, just over a ridge from where we sat in the truck looking for a push-out. We seen the wolf, on the large size. We grabbed our firearms & quick as we could trudged through some steep, deep snow covered hills & draws.
Once we crested the ridge[about 10 minutes or so later]. Here came both hounds back, slowly slogging along. Both hounds had blood plastered from the their head/face, down to their ankles. Bitten & slashed about the face, neck & upper chest areas.
We tended to the hounds best we could. Then we went over the rise, hoping to see a battered wolf. Wolf was gone, all we seen were battered hounds. They'd had their fill of wolf fighting.