If I'm reading it correctly, the assigner may choose to have officials evaluate each other:
At
https://arbitersports.zendesk.com/hc...to-Z#Officials, it says:
Lead Officials
A lead official is defined by the preference you have set. It can be one of two defaults: The official in the first listed position or the official who is highest ranked in the first listed position. Admins can choose the lead official on a game by game basis by editing the slot and marking it as the lead official. Each game is limited to a single lead official.
All Officials
This allows officials to complete evaluations on each other. Since officials can't evaluate themselves, if an evaluation only has the plate umpire selected to evaluate the plate umpire won't see an evaluation for that game (unless there are multiple evaluations). There is no permission or preference for which officials can complete evaluations. The permission to 'Select games to evaluate' is to allow evaluators to find officials to evaluate.