The person named on the card is the one that should be associated with the card.
If the card has a specific person named, that's who goes in the Name field and/or gets linked. No secondary/background people.
If the card is team-related and doesn't mention specific people (like a basic Topps "Team Card"), anyone in the photo from that team (but not an opposing team) can be linked.
If the card is game/event-related and doesn't mention specific people (like a World Series card), anyone in the photo from either team can be linked.
* Ed * L8 * Cards in my personal Collection are unavailable *