True, later high explosives worked better. Actually wounding an enemy is better strategically as it takes more manpower to care for the wounded , more food, etc, too, a dead person just needs a hole, or not even that.
Conceive's rockets were in use in the war of 1812, and included in the US's national anthem (the Rockets red glare).
Apparently they also were under development in the Peninsular war.`
I like the flank officer's sword....