The name that the Raw Input joystick driver pulls from the HID stack comes
from USB string descriptors contained on the device. For official wireless
receivers, this always contains "Xbox 360 Wireless Receiver for Windows"
which matches the friendly name that WGI provides.
3rd party Xbox 360 wireless receivers may have different strings in their
USB string descriptors (one uses "XBOX 360 For Windows" instead). This
fails to match WGI's name and causes Raw Input and WGI to both report the
same gamepad.
Since wireless Xbox 360 controllers seem to have a consistent VID/PID
regardless of the adapter enumerating them, we can also match on that to
catch these.
The duplicate case reported to me was:
Controller (XBOX 360 For Windows) - 030000005e040000a102000000007200
Xbox 360 Wireless Receiver for Windows - 030000005e0400000000000000007701
677dc1015c