Whenever I use nvidia-xconfig to generate my xorg.conf I cannot startx

I receive the error 'No Screen Found'
I believe it tries to start the Nvidia driver ONLY, not the integrated graphics which is required if I understand the Lenovo Y50-70 hardware correctly.
Removing xorg.conf allows me to startx again

I'm running 352.79 drivers from the guide on the Kali site (although commands like nvidia-settings are not found when xorg.conf isn't generated, settings must depend on xorg.conf?)
My system has Bumblebee installed my VGA setup is:
00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06)
01:00.0 3D controller: NVIDIA Corporation GM107M [GeForce GTX 860M] (rev ff)
Currently booting without a xorg.conf file
optirun and primusrun both execute but I'm unsure if they are using the discrete card...

What can I do to help xorg.conf find the screen (or rather the integrated chip)?

If we need any additional logs or outputs I'd be happy to supply them.
Thank you in advance!