The Trainer's Choice segment was full of errors with type matchups and stuff, but this one was the most egregious. My guess is the person writing them didn't actually know all that much about Pokemon and just made the assumption based on the fact that Jessie once had an Arbok and then had a Seviper.
https://i.imgur.com/lfI7zGE.jpg https://i.imgur.com/tgLNUuX.jpg
Come to the (un)official GameFAQs Touhou board. http://www.gamefaqs.com/boards/1110-