While that's a perfectly valid suggestion I think it's important to keep in mind that there are different levels of friendship. Perhaps the OP would prefer to retain the opportunity to be alone from time to time. Or maybe the OP doesn't want to smother his friend with constant company. I enjoy having company with me on the train, but I also enjoy having some personal space when I'm done being social. A sleeper compartment is a bit more intimate than sharing a coach row, kind of like a tiny hotel room. If a member asked us how to get his friend into the club lounge of a hotel would you casually suggest they share a room together?
New train (40-41 Floridian) between Miami and Chicago via Washington DC