You might want to check your access rules in your ‘Staff’ entity. My guess would be that the list view is correct, but that you only have read access to the ‘Player’ entity.
Hopefully, this helps!
Do you have staff records in the database?
I would test this by adding an extra listview in the same page and set Staff entity as datasource. If they appear in that list, they should appear in the Person listview with or without template for Staff.
So when they are not showing Then I would check if you have a constrained on your listview datasource.
If not, then you have found magic. And requires more detailed information on the model.