I think it's beyond awesome that you rescued all these animals! We rescued a pitbull ourselves and after 2 sessions of classes and regular training and exposure, he's an amazing dog! I love hearing about people rescuing pitties :3 we got so much negativity from people and still do, it's sad to hear it because these are the people that will allow a BSL law to get through...
I've heard people saying that "these dogs are bred for aggression, it can't be trained out" but I can't help but disagree. Our Ziggy loves any dog that ever lived! (well, not the greyhound in our neighborhood that bullies him, but I don't like her either XP) In my opinion, it's all about training, exposure/socialisation, and knowing your dog and his signs. I always know what Ziggy is thinking and I can get him out of an uncomfortable situation as soon as it begins.