The focus of this paper is to study the relationship between sporadic Fe (Fes) and Na (Nas) layers through simultaneous and common volume Fe and Na lidar observations. A total of 37 sporadic layering events were identified from one year (195 hours) of observations at Wuhan (30.50N, 114.40E), China. Out of the 37 events, 23 (62%) are characterized by the simultaneous formation of Fes and Nas layers. The most prominent feature for each of the 23 events is that the Fes and Nas layers occurred in overlapping altitude ranges and moved following almost the same track. On occasion the Fes and Nas layers exactly simultaneously reached their maximum peak densities at nearly the same altitude. These observational results strongly suggest that Fes and Nas layers are formed via the same or very similar mechanisms. This conclusion contradicts the previous suggestion based on those independent observations of Fes and Nas layers, that the Fes and Nas layers may be formed via different mechanisms. Out of the 37 events, 14 (38%) belong to single-species sporadic layering events. It is noticed that the formation of each single-species sporadic atom layer was usually accompanied by a weak density enhancement in the other metal atom. This supports the suggestion that Fes and Nas layers are formed via the same or very similar mechanisms. Both the Fes and Nas layers over Wuhan showed a tendency to strengthen with decreasing occurrence altitude. This tendency is consistent with the earlier Nas layer observations at high and low latitudes. Moreover, it is noticed by comparing the currently available Fes and Nas layer characteristics, which came from the observations at five different locations (including Wuhan) during different periods, that a lower average altitude could link to a higher average peak density and vice versa. The statistics-based link might perhaps represent a universal feature of sporadic layers. From our simultaneous Fe and Na density data we have found that the undersides of the normal Fe and Na layers follow nearly the exact movements and occur at nearly the same altitude. The normal Fe layer tended to be narrower than the corresponding Na layer nearly at all times, and this difference was generally reflected in the extent of the upper edge of the layer. The nearly persistent underside overlap strongly suggests that on the undersides of these meteoric metal layers there exist some sink mechanisms leading to the concurrent removal of different sorts of free neutral metal atoms.