I won't argue the point further than this message, and I appreciate the details you've provided, but the point of analogies is drawing parallels to quickly aid understanding at a surface level.
Nothing analogous to finding a needle in a haystack actually involves rooting through dry grass for a sliver of metal, but the analogy still stands.
I agree - but parallels can be a quick and effective way to communicate information where the specifics aren't important, even if they have to be consciously discarded for someone diving further into the detail.