I'd think a light gun sub-section would be more important than Soft 15 if we use thread length or views to determine it. Until recently, the major light gun thread was the most read thread of any on the entire boards. It's still the most read thread pertaining to arcade matters. It's almost twice as big as Soft 15 though it has slowed down tremendously.
Is there a reason people won't start a new thread? I only read about 20 or 25 pages of the light gun thread. Perhaps people should realize that a new thread may be better than adding to those two. Search first, try various answers that others' have posted, and then post additional questions if necessary.