[Beachinnole]

I've throught about this myself, it was a major tactic in the Arab-Israeli wars.

Also I was thinking about night turns and Illumunation rounds. I'm not sure low visibility just does it for night turns. You can have 10 miles visibility at night if something is back lit. But even is you had low visibility to simulate night an Illumination round could light up a 10 or so hex area. I got a first hand appreciation for what illumination rounds can do in Beirut and it is pretty dramatic when night turns into day.