Their are 2 naval ships in a grid 3km x 3km.
If you fire a K-4 to the target, how long would it take to reach the target area, what is the spread of the 80 bomblets and consider the distance the ship travels during the flight interval.
With these complex parameters, you will get a grid position of where these ships would be by the time a missile reaches the area in every possible case. Say the grid you need to cover expands to 10km x 10km, with that you could probably find out how many K-4's you would need to fire and spread to get a decent chance that you will get an impact by 1 or more bomblets. It's a numbers game for anti-shipping, but the cost of firing 24 K-4's to spread an area is nothing compared to the cost of a naval ship and time it takes to build one.