The answer is it depends. If you go by the scientific answer, one gives a wider image, but I can't remember which one.
The best approach is to use the manufacturer's horizontal angle spec on each camera. However, even those have been found to be a little off. I don't believe the camera manufacturers are very consistent, so the mm of the lens is really only relative to the same manufacture, and probably only to the same model. And maybe not then. I know someone on here compared fixed lens models to a varifocus and believe they found issues there. Use the spec sheet.