As far as my dogs go, we initially choose a boy as we were told that they tend to bond more towards women and our pup at the time was to be trained to come to work with me daily, so this was important. This however, didn’t prove true he just loves everyone!
We opted for a girl as our second dog, and were told the girls of our breed (Newfoundland) just love everyone. Not the case, I work from home now and she is obsessed with me, she likes the rest of the fam but she is 100% my dog and I am her person. So I don’t think there are any “rules” when it comes other than gender.