Humans being not all that behavior-dimorphic, I wonder if the non-dom partner in a relationship like Jeff and Misha's isn't as much alpha female as beta male. An alpha male without an alpha female might as well be dead, in evolutionary terms; only the alpha female breeds, and she will enforce that ruthlessly. Humans aren't as exclusionary about breeding, fortunately, but imposing a bipolar paradigm (sorry!) on a fluid system like a wolf pack means cutting out a lot of the most interesting relationships.