Wāw looks the same across these expressions, but the relationships supporting its use differ:
RelationshipPossible jāmiʿ
Zayd writes and composes poetryShared subject and related actions
Zayd is a poet; ʿAmr is a writerRelated subjects and literary qualities
Zayd is tall; ʿAmr is shortContrast along one common dimension
Zayd is a poet; ʿAmr is tallNo obvious bond without context
The aim is not to mechanize judgment. It is to recognize that identifying the precise relationship is an essential part of explaining waṣl.