You won't be able to put both on the same USB bus due to bandwidth limitations. I'm not sure how many USB buses there are on a Intel NUC but most computers have two USB buses (usually each connected to USB ports on opposite sides of the computer).
If you only have one USB bus, I'd try plugging both into a single USB 3 port using a USB 3 hub... I'm not 100% if this will work (it depends a bit on the webcam), but it might.