How do I apply these variations to artworks?

No.5937190 ViewReplyOriginalReport
And do they even matter to begin with?
For example, if you make a comic where you have to make millions poses of a woman/man; do you have to measure and apply the body variations for every inch of the body?
If I am going to paint;
Do these really matter?

If so, is there a way to memorize and learn them?