Rotts have the strongest bite. Shepherds, dobies, and pitts are roughly tied for second place.
Bite isn’t the only factor however. There is attitude. terriers have an innate meanness, a thirst for blood. They live to shred and destroy anything that moves or breathes, especially little furry critters.
Bulldogs have an innate tenacity to clamp onto the nose of a large adversary, like a vice, and hang on for the fun of it. They are thrill seekers...adrenaline junkies. If you really watch closely, a bulldog(old bulldog, not the current british bulldog) in action, they are not quite doing it out of meanness. They are half playing and enjoying the sport of it. It’s more like a game of tug of war with the opponents face. They will go after cattle, horses, anything that is really big. Something small will do if there’s nothing big around, but givin a choice, they will invariably go after the largest thing in their field of view. They can’t help themselves. I fully believe they would go after the snout of an elephant if allowed to...or the lower lip. The bigger the animal, the more irresistible the urge to clamp onto it. They tend to clamp on to any object in reach when they are extremely happy or excited.
Mix the two dogs together, terrier and bulldog, and you get a dog that is a potential problem. Pitbull terriers, bull terriers, etc. Also, terriers tend to be really stupid animals. Bulldogs aren’t too bright either, but at least they are loyal and make a serious attempt to please a master.
Rotts, dobies, and GSDs are highly intelligent breeds and very trainable. This makes them less dangerous. Well, possibly more dangerous if they are trained for that purpose. But certainly less unpredictable.
These are just my own personal observations. I like dogs and I watch them. however, I’m not too fond of terriers. I consider many of those breeds to be barely more than vermin. Especially the smaller ones. But I do have a soft spot for the bulldog type.
My American bulldog loves tug....and at 7 months and 70 pounds he is already a hoss
but so far he is extremely people friendly...his guard instinct is much less than the Dobies and Rotts and Alsatians I had at similar adolescent doggie age