How do three haired grafts usually grow after a hair transplant? I only see a few single hairs at 3 months.

My surgeon told me that he used many three haired grafts (to help match the density of my natural hair). I am starting to see just a very few hairs growing at 3 months. However, I don't see a single graft with 3 hairs in it at this time. How do these three haired grafts usually grow? Do they not always produce three hairs ultimately? Do they have a lower survival rate? I'm trying to understand what to expect. Thank you for your help.