If I might note: in the games defending an objective was usually all about interception, either of strike craft or their warheads.
What about playing on a 3*6 long and preventing the enemy strike craft getting into warhead range of free - double damage -w arheads?That way it could be like a double escort with one side escorting strikers and another escorting the VIP Corvette/raider/GR75/Gozanti/Frigate/BFF/your mom.