James, scale length alone isn't a determining factor, but you need the body style, scale length, and headstock shape to get close for the overall length of an Alembic bass. Certainly it would be just as simple, if not easier, to specify the overall length.
Thinking more on it, a Rogue might be tough to fit into a gig bag with the extended upper horn. Even worse, once it's in the bag, if the fit isn't great there could be pressure on that upper horn. I guess you'd need to pay attention to the body length of these as well when you're looking for a bag.