I think we need a way to have the ground combat module work for all ground targets (including atmospheric fighters). In real life, practically every fighter can carry every type of ordnance. The F18 Hornet can carry dumb bombs, GPS-guided bombs, laser guided bombs, unguided rockets, multiple kinds of air-to-air missiles, multiple kinds of anti-tank missiles, multiple kinds of anti-ship missiles, gun pods of varying calibers, extra fuel tanks, and ECM pods. And these are all attached shortly before take-off. You don't have to buy totally separate plane if you want to change from dropping bombs to shooting rockets.
I think instead, we should have one ground combat module that, when the fighter is launched from the mothership, must be set as to what kind of weapon it will carry. I would give fighters a higher chance to target their preferred target type as well. As a trade-off I would require the fighters to return to their carrier and rearm, draining MSP (or a new kind of supply, called "Conventional Ordnance" or something) from the carrier.