I have goats and chickens, I don't keep them together but they do cross paths every now and then. They don't bother each other though, I don't think a goat would deter a hawk from taking a chicken if they were together but my goats sure have a dislike for ground predators especially when they have kids.
So I think there would at least be some level of protection. My goats stomp the ground to scare off cats and they butt my dog if he turns his back and don't see em comin. Can't hurt to give it a go if you have predator problems.
My Nigis are in the same run with my chickens. They each have their own nighttime housing. Most days they are all allowed to free range and have the run of our farm. The chickens spend a lot of time in the big goat pens scratching through the bedding/poo looking for those wonderful treats!
Occasionally one of the goats will try to head butt a chicken but the chickens are quick and get out of the way.
I think the goats help with hawks - the hawks don't want to come down for the chickens when the larger animals are mingling in with them. Most larger predators will take a goat as well as a chicken (coyotes, medium to large dogs, cougars, etc.) although goats will often fight back and thus there is the possibility of a goat chasing off some of the smaller predators. I certainly would never assume my chickens were safe because they were in with goats.