Mojo, my aussie, was around 18months when he got neutered. He was a monorchid (undescended testical) so the vets opted that we wait that long to see if it would drop after adolescence. I must say that he was/is pushy, but he was a VERY dominant puppy, so I don't think that changed anything. I also didn't really let him play with other dogs, not that he didn't get socialised, but he was my obedience dog and I wanted his attention on me, not other dogs.
Faust, my GSD, is a big pushover. lol He is probably one of the wussiest dogs ever.
I believe that he was neutered around a year old. He has never been that interested in other dogs, so it was never an issue with him.
Tenchi, great dane, was done at 4 1/2 months because he lifted his leg on our couch. lol (Never again though!) He is a very friendly dog, but can be a little pushy/dense when it comes to other dogs. He's not unfriendly, but a little more in your face then some dogs like. I will never ever get a male neutered that young, or even before a year, again. I believe that it had something to do with Tenchi's height, build and joint issues.
I don't really understand the whole drive/neutering age thing, since Faust and Zeo have extremely high toy drive and were s/n in the midrange. What do they have to do with each other? Honestly asking since I never heard that.
Best of luck with Atlas, he sounds like he's coming along nicely. He is definitely added to my kidnap list.