We have a staffie. My lovely Sil breeds them.
We make sure Staffy has sufficient exercise (although tbh they are only fairly small dogs, they don't need that much) and that Staffy dog has toys to engage her 'prey' instinct. They were originally bred as terrier dogs so they are crazy for the whole 'chase it, catch it, give it a chew and drool on it' kind of thing. Dog toys, I mean, not peoples' legs or anything.
We have trained dd to not hit, kick, sit on, ride or in any other way torment Staffy dog. Staffies have a very high pain tolerance, which, really, is what enables them to be tortured clambered all over by children and not bother about it.
I wouldn't have any dog and not exercise or otherwise amuse it properly, and I wouldn't have any child in my home without reading the riot act about How To Treat Dogs and make sure I was there to monitor it.
Staffy dog has places to go if dd annoys her, although she has never been bothered. She sees dd as a playmate and not a snack, she knows never to jump up on dd, to always take her ball / treat gently from dd's hand, and she will stick right by dd's side if she goes out in the garden. If dd should wander where she is not meant to, like onto the drive or the back field, nanny Staffy Dog will alert us. If an strange adult or worse a strange dog is around, Staffy will protect dd as if she were a pup, standing and guarding her, chuffing or barking.
If upsets me that Staffies are so maligned purely because of their looks. When they have had loads of exercise they have massive jaw muscles, big shoulders and they do look hard. But that is just appearance. Staffy personality, imo, goes like this:
'Hmm I am a silly dog where is my ball play play ooh can I have a chip? thank you!
play play ooh yes stroke me stroke me hee hee see I can roll on my back can we play now oooh yes more chips gis a cuddle mistress I love you can I lick your chin oooh hmm nice'
They are stupid and loving and playful and very loyal.