(assuming that they can switch the mix instantly, because they have huge supplies of the different materials/components just sitting around waiting...)
I don't think we know at all what the spread is across the different launch countries, but it seems safe to guess that USA/China are getting proportionately more.
You could also say that it's not fair that we got to start placing orders at the relatively comfortable time of 8am, while folk in the US east coast had to get up at 0300 if they wanted to pre-order.
I very much doubt that there is any way this could have been done, such that everyone would agree it was fair