I was speaking pragmatically. It's like Kayneth versus Kiritsugu, even someone who is a horrible magus can take down an amazing magus if they hard counter the ability of the amazing magus, or are pragmatically "better"(Using cheat weapons like guns, or using martial arts on someone untrained like Rin versus Medea). In terms of raw ability, I completely agree with you, and even from a pragmatic standpoint I doubt this magus could take her down. She doesn't have experience killing DA's or High tier magi to pragmatically kill either.