Companions may be treated as a single broad generation or divided into further generations using criteria such as early conversion and participation in formative events. The Successors likewise may be grouped together or classified more finely according to the Companions they met.
Meeting a particular Companion, as opposed to merely living in the same general period, can alter a transmitter’s scholarly and chronological placement. These details matter when constructing reliable narrator histories.
The labels Companion, Successor, and Successor of the Successors are therefore useful starting points, but finer chronological and transmission differences may still need investigation.