Re: the
Your pup is 12 weeks old? At this point, you should be encouraging your pup to meet and interact with everyone (within reason) that you possibly can. You want a well socialized GSD. Loyalty will come. As long as you treat your dog well, train him, and love him, he will be as loyal as anything. And he is developing a strong bond to you as I type this.
Every time my puppy shows an healthy interest in someone (and the other person looks willing to oblige), I walk with my dog to the person, encouraging this behavior. We want our dogs to like other people, to be confident around others. This is a good healthy behavior. My adult GSD loves other people -- just adores them. And he is simply the most loyal dog I could hope to find.
If anything, the more confident you help your dog to be, I think it's likely the more loyal he will be. Not attached to you because of fear or lack of confidence, but proud and loyal because you're a team.