Aggression and maliciousness are not synonymous.
There is so much double talk in your posts I don't know where to start.
On the one hand you acknowledge aggressive animals... on the other you try to make it sound like its ONLY EVER a product of how it is raised/trained.
If these 4 adult dogs and 13 pups had been born in the wild they would learn to kill/hunt for food. If given the opportunity on some unsuspecting toddler they would try and snatch it in a heartbeat.
Furthermore your comment about aggressive animals "mother properly"... its bullshit, wrong, flat out not true. You should probably avoid topics you know very little about.
Keeping on the topic of dogs, some breeds will kill their puppies if their instinct tells them the litter won't survive over a given size. I worked for a guy who had a pitbull who had puppies, and the male (father) bit one of its puppies when it tried to get the dad's food. Not an uncommon response from dogs and food... however that bite went through the puppies skull and popped his eye out... the puppy survived but was disfigured.
This idea of kind and nurturing vs aggressive and malicious is you giving human traits to an animal. They don't exist not in the animal world.
As noted there are always exceptions but these "dangerous dogs" are bred for their propensity toward aggression, and their physical ability to be able to cause harm.