I dunno. I think there are more then 1 or 2 Cheron or Maxi types in Cali, or any state. They just might not think they are pretty enough or fit enough to model. Maybe they aren't quite as in shape and have a great body like Rachel or Chloe, but they aren't necessarily obese.
And then even if we don't rule out the obese ones, I think there are quite a few examples of still staggeringly huge bust to body ratios in larger women too. IF only we could line them all up and take measurements to work out what is the "magic" ratio. Like say, what is Rachel's bust to waist or height or hip or weight ratio compared to Norma's or Jodie 28K from "My big breasts and me."