There is also the fact that until the binding coil of bahamut we weren't certain that Nael was tempered and not too many people outside of you are aware of those details. Though I am certain that Gaius was trying to imply Midas was tempered.

As far as the resistance weapons, they could have been there as museum pieces before the garleans came in, they could have also been studying them trying to find out if the properties of the mystical versions of the weapons could be replicated much like we are.