Before any claim is paid, status as an insured must exist. Is the person or entity suffering or causing loss, injury, or damage an insured? If the answer is no, there is no need to go any further. If insured status does not exist, all your hard work is wasted; no one will ever find out how good you are at designing coverage because you messed up at the beginning.
If you mess this up, you will have a ticked-off insured and maybe an E&O claim you never expected. You have to get this one detail - the named insured - correct?