"I love the smell of CGI in the morning..."
I hate to say this but C.P.Vick's illustration is largely inacurate. The RSS-40 Courier is supposed to be a much smaller variant to the MGM-134A plans, so it being so much larger than the SS-24 is a large error. I think this diagram is simply speculation since most of the information is still classified AFAIK.
Keep the kids drug-free, maaannnn!!!!! ... wait, what were we talking about??
How would you know? Like you said, most of the information is classified, therefore any information circulating through the public should be nothing more than useless speculation no larger of a caliber than this.