Rockets do damage strike targets, but they do only a small amount of damage. I think you need 3 (direct) hits with a rocket to do 1 ticket of damage.
If you are trying to kill a fresh target just with rockets, it's going to take a very, very, very, very long time. Follow a bomber and scavenge targets he's softened up... Oh, and wait for the patch, because then you will be beating your head against this wall for a lot less time
