Adding another WHEREAS as you propose would be fine with me, so long as you can back up this claim. I have read things from John Lott along those lines generally, but I don't know if there is anything specifically proven about 'counties' or those specific crimes. And, if it is made too general, then it loses some of its semantic appeal.
So far, I was using mostly "moral" arguments, e.g., right to self-defense, unjust/uncompensated confiscation, and etc. Your argument is more of a "utilitarian" nature, saying that something good/bad happens to the collective if a certain public policy is followed. For me, that type of argument is somewhat less appealing.
Regardless, if you can back up the facts I will agree to another "friendly amendment".