Arrrg! That makes me so livid, how do they not understand when you say NOT to shave the dog?
Anyway, I didn't read the whole article linked above, but I thought i'd share what I learned about my double coated pup. I am hand stripping, so I pull the longest guard hairs (because he does not shed them naturally). I rake out the soft undercoat (called carding) with a deshedder tool so i'm left with mostly guard hairs.
It's the undercoat that grows much faster than guard hairs and plugs up the skin retaining heat. When undercoat is combed away, it allows airflow to the skin and a natural cooling effect.
I realise my pup's hair is not the same as aussie fur, but I use the Andis deshedding tool and it works like magic. As I card it encourages the wire hairs to grow in.
They start out all fluffy with a puppy coat, if I was to shave him instead of hand stripping, the hair follicles become damaged and undercoat takes over. If I continued to clipper, the wire would not regenerate and he would have a soft coat. But after one clipper, it's possible to revert back to a wire coat with hand stripping and some care.