I would not shave the whole dog if you already shaved the hotspots.
I have a large mutt with an insane amount of coat and I do often "lion shave" him for the summer, but he has a different coat than GSDs and gets hotspots with any amount of moisture. He doesn't even like to swim but it can get hot (80-100) and very humid here during the summer and many do not have AC so he is often "damp" even with us preventing him from swimming and starts developing hotspots. He's much happier with his lion shave. I wouldn't shave his entire body unless there was an immediate reason. The lion shave takes care of the areas where he usually gets his hotspots because those are the areas where his undercoat is very dense and his topcoat is long and coarse. Being a mutt, I don't have to concern myself with how his coat is supposed to look or feel. He also stays much cooler and more comfortable in the summer with his belly shaved (normally the hair there drapes down 8" long).