>>36607627Celadon and Saffron were the main areas of operation for Team Rocket, so... Maybe that's the reason Dark types were put in the vicinity?
>>36602870Let's remember Celadon and Saffron are based on the same city (Tokyo). The reason why this route is so short may be explained by the fact that it represents a park or something.
Fun fact, the actual layout of the map in the final game is almost the same as the layout presented in Capsule Monsters documents back in 1990, meaning this route was SUPPOSED to be like that from the very beginning.