Okay, the pod between the nacelles is only a warp field governor, not a weapons pod or anything else. I don't think a weapons pod should be placed there, since it has no forward clearance, so it would be a waste of space for it to be dedicated to aft weapons. I think the best idea would to simply have a multipurpose pod there in the style of the NX, with a docking port, some sensor palettes, and a glowing bulb (sensor dome?)