Height over bore, that is.
I’ve only half jokingly mocked other “future weapon” designs in the past, saying that the trend is toward an ever more clownishly high sight axis. My educated guess is that this is in fact a psychological problem.
With the lower velocity of the grenade/shotgun, it would make actual sense to put it on the bottom, with the flatter trajectory rifle barrel closer to the sight axis.
The new terms like “Soldier integrated such and such” (which obviously turn ordinary warfare into something totally new and different) are also the result of psychological problems. Years ago, while reading one of the supposedly big cheese U.S. military publications, I found that such a thing as an “army” is, technically speaking, no more. No, ladies and gentlemen; we now have a “Soldier-Centric Force Structure” instead, don’t you know, which no doubt changes EVERYTHING.
The advantage you see is that people who have actual experience in stuff are no longer needed, and can therefore be safely and conveniently brushed aside. Who needs an Army General when you can have a shiny, new, Soldier-Centric Force Structure Command and Control Engineering Specialist? Hmm? Was General Patton a Soldier-Centric Force Structure Command and Control Engineering Specialist? I don’t think so. All he did was lead an Army to kill a bunch of folks and break things. Feh!
And who needs a stupid old rifle when you can have something that looks like it came out of a bad Sci-Fi movie written by an ignoramus, and having the ergonomics of a cinder block?