Or, work the other way around???

Enlarge the whole Obj?
Select the body, and enlarge.
Then reduce all other groups sizes??
Size the neck somewhere in between head and the rest of the groups.

That works OK, and Eyes and Teeth stay usable!

Ps; you only have to downsize chest, abdomen, waist, hip,
ONE collar, ONE arm-hand-finger, and ONE leg-feet-toes ( on the same side )
Use the "Figure Symmetry" Copy from - to" with joints,  to downsize the other half.

Good luck, will take about 15 minutes of concentration.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!