Prone Squanderer
A bit of a Sillius Soddus.
I mean I get what people are getting at here they should of been unqiue NPC that would have the capacity to trap a Behemoth. Behemoths are mostly used as a game play feature though and not really much else. So yeah I would say don't look to much into however I do think it was a missed opptuitny to create a new faction or make the location its self more instresting. Like maybe the leader of the group had an idea to capture an animal or something and thye captured that or something. But yeah it does beg that question why generic raider would/want or be able to catch a thing. But there you are.
I do believe certain thing would just happen for example but why are there not notes/Terminal notes or etc explaining this. I can just imagine the raider boss being so dam pleased to capture that 'Thing' and that he plans to use it to take over megaton or soemthing. Ya know sometihng like that would of been cool but yeah just fuck it
I'd say forget the Behemoth.
Off the top of my head, have a situation like Evergreen Mills is still run by the raiders (or a gang of sorts) but they don't shoot on sight. The Madame has been abducting young women for her brothel and you're either tasked with taking out Evergreen or you could work for the Madame instead.
Or if you must have the Behemoth, have a plausible reason, say it was unusually docile or something. I dunno.