I think high to low is pretty standard. Admittedly on my '38 a heater was optional (dealer installed) and many folks went with a rheostat type of switch, as did I. My rheostat starts on high then gradually goes to low as the knob is turned. My defroster switch is the paddle type with two fixed speeds and it starts on high as well.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.