
I think that this depends upon the breed and personality of the dog.
All of my males, I have left intact and although they like to sniff the behinds of the girls, it never goes any further than this.
My last boy, who I lost this year was very confident and calm, he liked to establish that girls were girls but that was a far as it went and he didn't ever posture or start any problems with other dogs, although if they started on him, then a different matter, he could and would defend himself but he was certainly no trouble maker.
He also wouldn't confront my female, or anybody else's female for that matter lol. It was just unnecessary and too much effort in his mind.
Currently have a 6 month old boy and I will not neuter him unless there is a medical need. A friend of mine has neutered dogs that are always picked on by other dogs when out on walks and her dogs are very defensive as they are probably fed up with being targets for unpleasant behaviour.