Companions differed greatly in the length and circumstances of their association with the Prophet ﷺ. Some spent years in his company, others had shorter contact, and the documentation for some is limited. Their number of transmitted reports also varied. These differences do not change the basic criterion of Companion status.
Required: a qualifying meeting in faith and dying upon Islam.
Not required: lengthy residence with him, transmitting numerous hadiths, accompanying journeys, or participating in a particular military expedition.
Whether a specific report was actually heard and correctly transmitted remains a separate hadith-critical matter. Identifying a person as a Companion does not automatically solve every issue in the chain bearing that person’s name.