And when Ellis had them cross over to Planetary, it was under circumstances that prevented them from coming in contact with each other.
I'll just say this: the only Authority I've really found myself enjoying since Millar has in fact been anything involving Kev. Well, wait, Ennis' run on MIDNIGHTER as well. Come to think of it, Ennis' usual tone would seem to be perfectly matched to the Authority: ultra-violence, usually grotesque to the point of black comedy--check. An utter lack of respect for superheroes and their conventions--check. Underneath it all being driven by an engine of very secular morality(the drive to make a "finer world")--check. I'm surprised Ennis hasn't done the regular series, really.