The one friggin' word I actually didn't ask Auntie Wiki and Uncle Google about.
Wiki knows nothing about Bruchmüller's task-oriented artillery group system, and barely knows that he was involved with artillery at all. Google is slightly better, but very misleading; it's possible to locate the texts of some of the monographs written on Bruchmüller and his system via Google, but they're buried under mountains of garbage if your Google Fu isn't top-notch, otherwise you'll get dragged down the "did you mean schwefel?" rabbit hole and never emerge.
Still, how is that related to 1943-1945 Flugabwehrkanonen and B-17/B-24 formations remains a mystery to me 
(USAAF = United States Army Air Forces, the WW1 equivalent would be the USAAS or United States Army Air Service)
Nothing whatsoever. It was about the amount of "fire" Fiona was taking. Because as much fire as an American bomber formation would have to endure, I have a feeling that a Great War army group could dispense even more.