> What if your inquiry needs a combination of multiple sources to make sense? There is no 1:1 matching of information, never.

I don't see the problem if you give the LLM the ability to generate multiple search queries at once. Even simple vector search can give you multiple results at once.

> "How many cars from 1980 to 1985 and 1990 to 1997 had between 100 and 180PS without Diesel in the color blue that were approved for USA and Germany from Mercedes but only the E unit?"

I'm a human and I have a hard time parsing that query. Are you asking only for Mercedes E-Class? The number of cars, as in how many were sold?