My boy got one at 8 weeks and 12 weeks. My vet says two more. One at 16 weeks and one at 20 weeks.
I thought that sounded like a lot also, but I really trust my vet so I'm going to follow her judgement.
That's excessive (old protocol). I would make the 16 wk shot the last one, then do rabies at 18 wks (or when your state law mandates but not at the same time as the puppy shot).