You made me curious so I looked up a couple charts, which ones have you been using?
I overlaid the charts over some people I found. The first one is a model, I'm not sure how accurate but she was supposed to have perfect proportions for a model. She seems more like what you are describing as her upper half is shorter than her lower half. She is almost exactly 8 heads tall.

These 2 are just regular girls.


The 2 regular girls seem to fit into older drawings that are classed as ideal. The 3rd drawing is newer and is still classed ideal and is 8 heads where as the others are 7 and a half I believe. I'm not sure who the original artists are for any of the images. Also only the middle image has the same length of upper and lower body.