i had an idea for this. Instead of just giving them goliaths and tanks and stuff you should do a virtual hp set up. Then you can customize stuff so like
P1 has a "missile" and a goliath body when the goliath kills the virtual hp unit then do a graphic for the "missile" attack going towards the enemy you shoot.
This isn't all that great an idea but it is somewhat better then just using goliaths or tanks to shoot it out