Is there a performance gain or best practice when it comes to using unique, numeric ID fields in a database table compared to using character-based ones?
For instanc
The standard answer is to use numbers because they are faster to index; no need to compute a hash or whatever.
If you use a meaningful value as a primary key you'll have to update it all through you're database if the team name changes.
To satisfy the above, but still make the database directly readable,
use a number field as the primary key
immediately create a view Athlete_And_Team that joins the Athlete and Team tables
Then you can use the view when you're going through the data by hand.