that "sweeping bombardment " thing goes back to ww1- but EVERYONE has to be on the same page- it was a favorite of the 'empire"( not starwars) but the infantry had to advance at a measured pace and the arty laid down fire in front so many yards- there's a formula( you know how brits love math) which was blast radius plus feet- just the same as live fire during basic- the one where you crawl under the barbed wire and the machine gun is set at about 6-0 feet above you- some armies STILL train that way