This has sense. The best civilian ship is one that does not exist, but we don't get resource reduction for it. Guarding civvies is a problem, if they are destroyed without loss, its the best. Most likely they will destroy an 1-pop ship, which means we are free from trouble of one ship. The problem is is it destroys a 2-pop ship, but we still get it destroyed at a reduced cost.I suggest that you close the one that is not at the space yard, let that one here take away a ship that will likely not effect us at all thanks to your preventive policy.
But if Jacob insists, destroying the one attack the ships is fine too.