Difference in buzz or shave for healthy hair?

My friend who is recovering from trichotillomania has very damaged and thin hair. She’s now decided to get it shaved to start new and get fresh healthier hair.

Im just wondering wouldn’t it be smarter to just buzz it? That way you don’t wait as long for hair to grow back right?

Or would completely shaving her head be better at getting healthier hair then just buzzing? Is one more advantageous then the other in getting rid of damage hair and growing healthier?

I suppose if her hair was damaged it would be better to shave off the damaged hair