Being bitten by a cocker or a terrier is no where near the same, you are so much more powerful than the dog.
It isn't just that.
Most breeds have a "bite inhibition" - that is, they will snap, or even bite if they are provoked, frightened, or over-excited when playing, but then realise what they have done and stop. Their bite is effectively a warning of "you've gone this far - but no further" and they don't go further either. Almost all dogs, when fighting with other dogs, will accept a "surrender" from their opponent and stop when they have won. Very few dogs put their full force into a bite - they hold back because instinct tells them that in a fight they could also get hurt.
These XL bullies:
a) have been bred to enjoy fighting - they get a huge adrenaline rush from it. This not only makes them aggressive but also anaesthetises them to much of the pain an animal would normally feel when being bitten/ struck. Hitting them to "get them off" just increases the violence because they see themselves as under attack.
b) have a very hight prey drive. The yelping/ screaming/ whimpering of their prey excites them even further. They don't accept a "surrender". They just continue the aggression.
c) they are very dominant and know their own power. Most breeds again, accept that their owner is the one in charge. These dogs don't seem to. They are very aware of their own strength, and as a previous poster wrote "you are in charge until the dog decides you aren't". They don't hold back because they know they are powerful, and they know that their opponent doesn't astand a chance (unless it is the same breed, of course - but then it would be a power struggle to the death anyway, as neither would give in.)
d) they are unpredictable. It seems many give no warning growl, and just attack - and the attacks can come out of the blue. Once the first move has been made their prey drive kicks in and they are almost impossible to stop - they really, truly, get into a "zone" were they are unaware of anything around them - all that is real for them is the creature they are attacking.
e) they fight/ attack because they enjoy it. Not because they have been abused, not because they are threatened - because they ENJOY it. This can't be over-emphasised.
Add this to the sheer size and strength of the dog, and you have a killing machine that can't be trusted.
I have seen a dog in this state - not one of these thank heavens, it was a very bad bred and over-aggressive border collie - and it was the scariest thing I've ever seen in my life.
Edited to add. Many of these will also have been encouraged to attack and kill smaller dogs and cats. The sort of people who weaponise them will do this (so never re-home your pet if you don't know exactly where it is going). And it wouldn't surprise me if many o them had also been encouraged to chase and snap at people.
So well-explained @Emotionalsupportviper . This post should be copied onto every thread about these monstrous genetic abominations. They have no place around humans.
I think actually rather than prison sentences the owner of these dogs should be locked in a room with a few of these dogs and let nature take its course. If they are all "soft cuddly little teddy bears" then I'm sure they'll all be very happy with this arrangement - a couple of days of cuddling up with a group of these cute, fluffy animals than they think make really fun family pets rather than years of prison. No reason for them to resist that, surely?