Participants are introduced as they come on the scene. If the participant is foreign there needs to be a longer introduction. If there is a personal connection with the participant it could be stated to help connect the listener with the story. If there are multiple participants, it can become necessary to refer to them with names or nouns instead of just referring to them with the verb endings. In that case, reusing names and nouns is more for clarity than to establish prominence.
The Kovol language makes use of verb affixes as it's primary way of keeping track of participants. Participants are introduced with phrases, proper nouns our pronouns and then the action is tracked using verb affixes.