>>49036310It is quite simple to understand that fish-like Pokemon, such as Seaking, Wailmer and Sharpedo, cannot move on land. Hence, it is stupid to let them battle on land.
This is supported by the anime as well, where Misty's Goldeen is useless when called out to fight on land.
Conversely, it is equally stupid to let non-Water Pokemon to battle when diving and non-Water and non-Flying Pokemon to battle when surfing
