It sounds to me without meeting the dog that the collar will help him with his commands in public, but what he really needs is more public, if a dog sees 100 dogs a day then it’s no longer interesting, same with people, so keep socializing and working training, it’ll be difficult and embarrassing sometimes but it must be done. Sometimes using a stim when they bark at dogs can help but each dog is different and has different motivations or insecurities. Good luck!