Keeping the camera clean is another important issue. Without constant maintenance the effect will only look right at first setup degrading over time. What were you thinking with having multiple lenses, how would that solve some the challenges?
For redundancy. Chances are all the lenses aren't covered in spiders. If you have two, you could select the non-giant spider view, or even write up a quick and dirty script for deciding which camera seems to have the minimum number of giant spiders at any given time, then select accordingly.