My pit bull wouldn't do shit. He doesn't even bark if someone is in the yard. Now, my GSD mutt will bark and snarl but won't back it up. My Coonhound, however would possibly/probably maul a person if they physically threatened me or intruded uninvited onto HIS territory. A Coonhound is definitely not a guardian breed but he didn't get that memo.
ive been around many coonhounds that were very protective my neighbor has a red bone that i assure you is as good a guard dog as any GSD or dobie