A further question is whether jism functions as the name of a class of things or merely as a descriptive term for bulk. This affects how far one may argue from ordinary language.
If “body” is a class term, one body can be larger without possessing more of the essential classification. If it is used only as a description of size, the subject of the discussion has changed.
Sound analysis first identifies the technical meaning intended by the speaker, and only then asks what linguistic comparisons can establish.