You do not want to risk injury or intimidation on your new puppy.... I would do very slow socialization like I did with my older dogs.. About like this to be safe:
I have two older GSDs one Alpha Male sort, one Bitch, 10 and seven years old... I kept them apart from the puppy, through the hog wire fence. After a week, they were licking socialization and acceptance.. I reprimanded any growling or grudging behavior..
First week, no real contact, through the fence contact only... This progressed until they gaurdedly accepted him, and would lick through the fence in recognition..
Second week, I guardedly started to let them out on walks, but kept the puppy on a lead and kept them back a bit..
Third week, puppy off the lead as long as they were fenced off, and they readily accept him... With the pup on a lead, now we all go on walks together...
Fourth week, they accept and play with the puppy kept on a lead. At 14 weeks now, they play with pup a bit. So they don't run past at speed and dump puppy over, pup will stay on a lead with them until one year old and bones harden up. After this month, he is one of the Pack, a junior member.
I hope this is a help...