I'm just wondering why people believed those rice paddies were tiny to begin with.
My dad was born and raised in Cambodia. He grew up on a rice farm for part of his life, and he went fishing in the rice fields all the time. He caught a lot of betta fish, and ate the "normal" looking ones, but kept the "pretty" ones as pets. The rice fields are generally filled with a lot of water, by no means any "puddles". Those puddles would only happen when the season was over and the water naturally drained away or evaporated. The betta fish that didn't swim away before either of those two things happened would simply die shortly after. Other than that, bad rain season.