Welcome back, Owl!
Rockets could possibly be easier to use than aiming a cannon in some cases. With rockets, you should be able to get a very high velocity so gravity isn't a problem, and the massive damage and area of effect make pinpoint accuracy less important. Some of the ACL maps are so tight that anything fired along a line of sight to the target is likely to do damage.
I would expect that any swarm would overwhelm (or even be ignored by) the targeting system of most bots, so a swarm of guided missile style bots could be devastating if the attack was properly coordinated.