Trace isn't afraid of anything or anyone....which may be a good thing or a bad thing....any way, I suggest socialize, socialize, socialize. That's what we did with ours. Btw, their was a German Shepard in puppy kindergarden who was terrified of the other pups
He hid behind his mother the whole time, so it's not just a size thing....LOL. He was bigger than most of the dogs there. His mom enrolled him to specifically get him over being so timid around other dogs