Once they hit Chang the first time or two, they could've just as easily ordered a tractor beam without losing any time or the battle.
If you think there was time for that sort of mucking around have another look at the clip. The first Torpedo was just a marker. No guarantee how much damage it had done and since they needed to aim at the explosion as soon as possible, not Chang, each ship would have had to fire a (seemingly staggered) salvo (2+2 or 2+1 etc) to make sure enough hits were achieved to neutralise Chang as a threat. The only problem was both captains had the same idea and that may have over cooked things a little. At most that's an Oops! Or hard luck! Combine that with Chang's ship's limited defensive abilities and the result was inevitable.
There is no way either captain could afford to fire less that 3-4 rapid shots in that situation. Probably their instincts took over and prevented Kirk and Sulu from having a "conflab" about how they were going to handle things!
To expect Kirk and Sulu to coordinate their attack so that the each fired only one shot alternately and then waited to find out the effect (They could have missed entirely), is ridiculous and obviously dangerous. Certainly not a chance they could take given the circumstances. There is clearly no problem here.