It would make more sense if it wasn't the only option. For example if it was that line and the suggested "we keep protecting each other". Also, as Durge you can tell the butler "we're indomitable together" during that Act 2 scene. I'd like to be able to say that to Astarion himself. "You don't need the powers of the ascendant. Nothing can stand against us together" or something like that.
