I've had three dogs before (not all GSDs) in different combinations. I do think it can be harder to take them all along places. I know it's possible to walk 3 at once but I found it a lot more comfortable to have another person so I could walk 2 and they could walk one. Of course I usually had 3 different-sized dogs which was a little harder to work with than if they were all the same size. Walking three makes things more difficult, especially going to events and outings. Even when I just had two dogs at events/outings I usually would have another person along if possible, so I could hand one dog off if I needed to or if I wanted to do an activity being offered I could have the other person hold the dogs in turn while I worked with the other. When I haven't had an extra person (like at dog camp) it was more of a hassle with two dogs and made everything take a little longer.
I think if I lived alone when I had multiple dogs it would have been a lot different, as it was I was the sole caretaker, but at least there were other people to also give the dogs attention and sometimes accompany us to events and things like that. I have also noticed that when I've had three, they show more pack type behaviors which my dogs never really did when it was just two.
