In their spectrum of activity as NON STEROIDAL anti-inflammatory drugs, Paracetamol is fast acting, but weak on anti inflammation, while Naproxen starts acting much later but strong on anti inflammation.
Medical wisdom would question their synergy as it relates to pain, but conventional wisdom based on the above understanding is why not. If it helps.
The following conditions need to be fulfilled though.
They have to be taken WITH FOOD.
After the pain has eased a bit(3-5days) Paracetamol need to be withdrawn.
It can be introduced back if there is a flair up on the same conditions.
THE BEST combination is with a mild narcotic like codeine, (which unfortunately you do not tolerate)