I too am more than happy to review this. I'd say some of the problem also comes from our underbelt. The CRL currently gives that as:
"Approximately 2" (51mm) in width, up to 3" (76mm) is acceptable." (underbelt)
Compared to:
"The waist strap is approximately 1.5" (40mm) wide." (overbelt)
On a 76mm wide underbelt, a 40mm overbelt probably would look fairly close to the in game references (relatively speaking). However 76mm would be very large for an underbelt, and I'd guess most would be closer to 50mm (my own belt included). On a 50mm belt, a 40mm underbelt definitely looks too big.
So I would be perfectly fine allowing more latitude on the overbelt exactly as Dennis suggests, changing it to "approximately 30mm-40mm". The important part is that the two belts look correct together. If we allow a range of widths for one, we must do the same for the other.