Fitting missiles under the wings of a ship is one thing, fitting three (you can't adjust how many are shown on a per weapon basis) missiles into an opening without knowing how big the missiles are is another.
If I space the weapon points and make the opening big enough so I can fit three harpoons/interceptors so they're fairly close together and look good three tempests will look weird just floating there. Other missiles are different sizes as well (although not as much as, say, a bomber that can carry Tempests and Cyclops).
The other scenario involves modeling three generic missiles in the pods and whatever you fire launches from them. When you're empty; they're stocked. When you're mounting X weapon; they're still generic missiles. If we're going to have a generic model "plate" over/around the missile launching area why not just make it like all the other fighters?
EDIT: If it gets to be too heated of an issue, why don't we see if two versions can be produced and compared? (if peterv is willing, of course)