I hate to put so many Kantomons in here, but like
>>51610521 said, I think Gen I is the basis for what the types are aiming for. I tried to base it off of how the types play, the lore of the Pokemon, and what most people would consider first when thinking of a particular type.
The birds seem like the embodiment of their type, Mewtwo has always been King Psychic to me, same for Groudon. It was between Dragonite and Corviknight for Flying because they've been established as basically the best fliers in the Pokemon world for delivery/transport.
