Do Single-Hair Grafts Have More Successful Growth?

Does the single hair graft and double hair graft affect the survival? which one has a more successful rate? Example: a doctor likes to claim that in eyebrow transplants you will get single hair grafts, which make eyebrow transplant more successful. Is that true?

If the surgeon knows what he/she is doing, it does not make a difference. In fact, if one divides a two-hair graft into two one-hair grafts, then there is a risk that the growth center, which is largely located just below the sebaceous gland, could be damaged resulting in the death of that particular hair. Making one-hair grafts out of two-hair follicular units is a special skill obtained with lots of experience.

Just to clarify as well: eyebrow transplants are not any more successful than a scalp hair transplant. So the argument of a one-hair graft being more successful, in my opinion, is not valid.