Hello dog obsessed,
That's a pretty funny problem
I would think getting him fixed would help with the humping since the urge to do that would be minimized. But I also think this is normal/natural behaviour for dogs. Even females will hump stuff sometimes even when they are 'fixed'. I have never had this problem with my dog but I have seen other dogs do it.
I saw a dog behaviour show with a situation like yours on it and the reason the dog did this was to show dominance over the other dog. Does he do it to just females or males too? If it is just females then maybe it's just the hormones (his natural reaction to do this) but if it is males too maybe he is trying to show them he his the boss or the 'stud'
Another reason for excited behaviour is if he hasn't been around a lot of other dogs then he will get excited to see them. Once he starts being around other dogs more and getting used to that then he should calm down. Getting him fixed will help calm him down and improve his temperment. If you are worried about socialization then you could take him too obedience classes where there are other dogs or a odggy day care where he can play with other dogs and get used to that. But, most places want your dog to be fixed before they will take them so any mating won't happen
You can call around to different places and ask what their policy is on that.
Good luck!