>>41975841Gen1 tried to excuse the existence of its types, for example:
Created pterosaurs, and bats to justify replacing the BIRD type to the FLYING type.
Ground was a balancing type, like dark, and was slapped on to any creature baring those design themes of beefiness, but they had to give it some validity on its own. Thus they came up with the digging theme for digglet and sandslash. Then they made it fast and frail, on purpose, as a complete opposition to its theme, as a joke of sorts, but also gameplay variety.
Sandile is a thick-scaled creature. It fits in the primary ground category of thick-skinned creatures like armadillos, hippos and anacondas. The sand theme is almost superfluous, but it links to real life crocodiles.
Gible? Lorewise is even a flying type! The sand theme is extremely weak and the hard skinned theme as well. Pure Dragon, but the sand abilities should remain.