shivans can use unstable jump nodes, remember? the sathanas got through without a knossos, so why cant more shivans get through? you'd want many powerful ships that require minimal crew (and perhaps even automated ships, or atleast turrets). and they would probably replace blob turrets with something better (FL style ion cannons, fighter weapons, more beams). the fs2 fleet was, after all, the fs1 fleet with streamlining and beams.