Dunbar's a familiar name and in good standing so far as I know, and I know that Tooby and Cosmides (though brilliant) have a tendency to go too far occasionally (e.g. questioning whether humans actually have any such capacity as general intelligence, which I should maybe talk to them about one day). It sounds like you can trust the handbook for an overview of possibilities and current developments, but remember that openness is a different stage of inquiry from saying that all those ideas are actually right. For example, Wilson's multilevel selection as a mathematical formalism is tautological, I think, but it's a big step from there to saying that we should frequently see group-level pressures overcoming a countervailing individual selection pressure.