How to sculpt correctly?

Question

3D

Hello! I'm learning zbrush from tutorials and one moment is not entirely clear.
On some tutorials, it is advised to sculpt a person from a very small number of polygons. It's about head sculpting.
That is, in terms of training videos, they teach you to start from the lowest level of a subdivision (literally create a base of 6000-10.000 asset points) and only then move on to the next level and so on.
At the same time, in other videos, and in general in most of the time-lapses that I see, sculpting starts already with 50,000 points or more, some at once almost half a million.
For example, here is the course. https://www.udemy.com/course/female-character-crea... (the first few videos are free, in particular the lesson "Starting the head from sphere")
Here he works for 20 minutes at the lowest level of the subdivision.
How to sculpt properly?