Carriers almost always have double drone control in SFB. Presumably they would be controlling not only their own drones, but others "in the air" from ships in their fleet. Generally (there are always exceptions), the normal cruisers will have drone control = sensor rating, but bombardment ships and carriers would double up. Heck, there are some ships with just 3 drone control.
"G" designation on an F-DDG or a BCG is meant to show it is a "guided weapons" upgrade/variant. That doesn't mean it's a bombardment ship, just that it opts for a couple drones in addition to, but not to totally replace, photons.