Correct me if I am wrong but I think you're thinking too deeply into it
Mind you, I've been working 16 hour days this week so my mind is a bit kaput right now.
If I have a Nikon D810a with a nifty fifty using at F/4... This is what it is. Let's say now that I have 100 of these setup all pointed at the same thing. It is now effectively working as a 50mm F/1.26.
All it does is explain the light gathering power of an image, a way of expressing it in a way of single exposure. This means, 100 cameras all taking a single 120s exposure at F/4 would have the same SNR as a 120s exposure at F/1.26.