In this specific scenario, it isn't so much the quality (a valid config), it's literally adding URL rewrites that do nothing because they are unnecessary and don't exist in the documentation, it also not infrequently modified them, meaning that it wasn't what I'd given it.

Not being able to do simplistic tasks like this really makes me doubt the claims of others, either that or what they're doing is complete shite and they don't even know it's shite. IMO, it seems likely that there's a lot of highly inappropriate hires who are actually outdone by an LLM, which says more about them than the LLM. It's a very low bar.