Hi,
I guess that there are several possibilities, which mainly depend on what you would do with all this data, and if you will continue adding more data from more sources in the future (like NHL? )
You can either extend the nms:recipients schema with a few fields to indicate their nature and role. For example one extra field for sport (can be NHL, NBA, etc.) and one other for their role (referee, player).
If the structure and needed fields matches from one sport to another.
If there are too much differences to anticipate, I'd recommend creating new schemas for each, to ensure your database and recipients schema does not become hard to maintain and understand/use.
Other question to take into account is: how much do you need to have them under recipients (vs. creating new target mappings for each?)
Do you have ways to test that in a test environment?
Florent