I don't how it's being used there, but I do know the Lord Of The Flies - it was one of the set English Literature books at my school!
It is a poor metaphor because the characters in the story do not really break into factions.
It is about a bunch of English school boys on an evacuation flight from a war - the location and circumstances are not clarified, as I remember - when their plane crashes on an uninhabited tropical island, killing all the adults on board but somehow leaving the boys unscathed.
Most of them are from a "public school" (British definition, i.e. private) and rather full of their own self-importance, especially the one (Ralph?) who becomes a sort of de facto leader apparently for no other reason than being head chorister in the school. There are however a few others from more ordinary backgrounds, and the most senior of these becomes the victim of the Ralph and his chums, as their civilised veneer crumbles.
It is a narrative of their failed attempt to survive in a fairly civilised way, and breaking down to what is really a fight between just two boys; one thinking himself socially superior to the non-public school boys by default, and superior to his own pals by his status and singing ability in the school choir (as we learn from his own boasting early on). .
So no factions as such - most of the other boys just string along without really understanding what they are doing, or because they were in Ralph's choir.
[I think Ralph was the name... I have not read the book since then, and that was a good half-century ago!]
Thank you for the thumbnail sketch of the story Durdle. I have heard of it but never read it nor read a synopsis of it. Of course politically here in the states one of your lines jumps out at me! "...most of the other boys just string along without really understanding what they are doing...." The FOOTOO adoring worshippers fit those shoes in my opinion. Either that or they are all evil as is he. Even worse they will never understand that what they have done is unbelievably anti human anti humane and anti democratic. They believe they are the patriots. We know better. How it will play out here I don't know. Hope all is well with you and yours! :)
Durdle 