Classify the relation, not just the punctuation or absence of a conjunction:
«مات فلان، رحمه الله» — a report followed by a prayer: complete disjunction in communicative force.
«أمدكم بما تعلمون، أمدكم بأنعام وبنين» — a general statement followed by specification: complete connection.
«وما أبرئ نفسي، إن النفس لأمارة بالسوء» — an explanation responding to an implied “why?”: istiʾnāf under near-complete connection.
A correct analysis brings together wording, relation, context, and rhetorical purpose, not merely the presence or absence of wāw.