Something to consider...

When I built my own little tweak (further up the thread), I only barely breathed on the overall body scaling. The meat of the scaling occurred in the body parts - decreasing yScale on the vertical ones (hip, abdomen, chest, thigh, shins, etc), and decreaing the xScale on the horizontal ones (shoulders, forearms mostly). 

When you attack it piecemeal like that, you'd be amazed at how little you have to scale down each part to get a huge overall shrinkage. It all adds up. :) 

It also gives you some options to more closely match the variety of real human beings... like mentioned up top, some of us are a bit over-provisioned on torso, while others have more leg proportion, while still others have more chest, etc. The petite girlish mesh up top was engineered to have more torso in proportion, so I concentrated on everything around it. 

Note that I scaled in the arm bits to prevent the poor figure from becoming a gorilla. It's usually good to have the wrists about (roughly) even with the mid-hip, where the hip joint would normally sit. Too long and you have a gorilla. Too short and you end up with a T-Rex. 

 

The best bet to get an eye for scaling up or down is to look at full-body images of a lot of people, preferably from the side and front. A line-up of folks would be perfect... because then you can draw horizontal lines through the hip joints, the pelvic crown (the top of where the hip bone would be), the xyphiod process (bottom tip of the sternum - whatever that's called), the ribcage bottom edge, the inside ends of the collarbones, the shoulder tops, etc. Avoid nipples (esp. on females, since they'll be all over the map). You'll notice that not only are people different in height, but they're different in proportions as well... sometimes good, sometimes not-so-good.

 

That's what I'm hoping the character merchies will get off their lazy butts and do. :)