I think I know what you mean.

[Stroking her chin, she recalls some training she did with her partners yesterday.]

I haven't noticed it as significantly with Monkey, but Abbey fights surprisingly well against some of the ghost-type pokemon I've encountered in the city. If I correctly recall the entry I saw on her species in a book I read, that wouldn't add up unless what you're saying is true. There's nothing about ground or flying types that should have an advantage over ghosts.