https://bugs.winehq.org/show_bug.cgi?id=52408
--- Comment #1 from Rémi Bernon rbernon@codeweavers.com --- Gamepads are usually exposed to Windows applications as XInput-compatible devices, and the Windows XInput API only supports up to 4 gamepads. This is not a Wine specific limitation but a limitation of the API itself.
Wine control panel now has an override button to force the joystick devices not to be recognized as XInput-compatible, and although some games actually only support XInput for input, it will remove the device number limitation in others.
I'm working on implementing Windows.Gaming.Input API which supports XInput-compatible gamepads, and doesn't suffer from the limitation, but there again only games which implement support for this API (ie: using some recent version of SDL) will benefit from it.