The right number of dogs vary for the person. My two dogs are such high energy and crazy dogs that I know there's no way I could handle another one. Yet, they get along so well together and play with each other all the time, and are inseparable, so I wouldn't have wanted to have only one of them. Both dogs came from a shelter where the previous owners said they were too much and a handful, so I think it takes a person with time, patience, multiple people in the household, and a budget to take care of the dogs. Luckily, we have a whole family in the household working to take care of them, and with everyone's work schedules, there's almost always someone home to take care of them. You can't be lazy with these two, either, so if you just say "no, I don't feel like going for a walk today", then these dogs are definitely not for you.
It depends on both the dogs and the people as to how many are the perfect amount. Of course, the animal hoarders who have 90 dogs in a small house are just plain abusing the animals. If you can't adequately take care of every one of your animals, you have too many animals.
