At this point, it's pretty much just a question of definition, so I'll leave that part of the topic to wikipedia
And no, unless I'm missing your meaning, the crusader was not firing cluster shells (as in, a single shell that splits in the air), but really 8 shells, fired independently.
But with Rayhawk's rule, I'm gonna have to include some cluster shells in one of my games.
On another almost off-topic subject, I though of another heavy weapon that should be efficient against individuals. Heavy machine guns.
Suppose you take a size 3 gattling gun, and just try to get a few rounds in the mini in front of your construction. Since most of the gattling's damage comes from the numbers of rounds that hits the target, how would you represent the random spraying on a few small targets?
I though, perhaps, of giving the option to drop the damage (and maybe also the range) of constructions to drop the use rating as well.
(ie: dropping the size 3 weapon to a size 1, doing just 1d6 of damage but at use 3, to increase the chances to hit a small target at the cost of damage).