Device assignments
If the PlayerInput component has any Devices assigned, it matches these to the Control Schemes in the associated action asset, and only enables Control Schemes which match its Input Devices.
Each PlayerInput can have one or more Devices assigned to it. By default, no two PlayerInput components are assigned the same Devices, but you can force this; to do so, manually assign Devices to a player when calling PlayerInput.Instantiate, or call InputUser.PerformPairingWithDevice on the InputUser of a PlayerInput.