The idea behind cycling weapons, at least in a game like this, is to increase the rate of fire of an otherwise slow-firing weapon. Using the four turret example, if you had cycling on, the weapon would fire 4x faster but only one shot would be fired per burst. However, with cycling off, four shots (4x damage) would be fired at normal speed (1/4th the speed of cycling on). The problem with designing a weapon like this, as I see it, is that with cycling the delay between shots must be inversely proportional to the number of banks, so that each bank fires a shot as slowly as the weapon would normally fire. This seems like a setting the player may want under his control, so that he could, say, link all shots together into one burst or cycle to increase rate of fire.
On a side note, missiles already do this, so perhaps some code could be adapted from there.