one could not say ‘a green great dragon’, but had to say ‘a great green dragon’. I wondered why, and still do
Tom Scott to the rescue: Adjectival Order: Why A "Big Red Balloon", not a "Red Big Balloon"?
TL;DW: There is an order, we mostly agree on what that order is, but we still have no idea why. ¯\_(ツ)_/¯