does your teacher mean that people tend to get a B when exploring frankenstein or ATSS?
if they’ve advised you that one text tends to disadvantage you, id potentially heed that warning unless you’re very confident. you’re going to have to write a lot about it and you don’t want to get ‘stuck’ midway through because you can’t find enough to write about
if you’re struggling to find comparative texts, i’d potentially consider other ideas to explore or even other novels! for my coursework (granted, combined english rather than pure lit so we were comparing a literary and non-literary text) i went through about 5 different ideas and combinations of texts before i settled on my texts (The Secret History and a true crime podcast episode)