I'm all for idioms, and I understand the sense of them, but I'm against the ones that rely on
logical fallacies (e.g., the bird/feather one, which interchanges whole and part). Perhaps I just don't like synecdoches, which are "A figure of speech in which a more inclusive term is used for a less inclusive one or vice versa, as a whole for a part or a part for a whole." (
OED).