Hello Ramma,
Thanks for getting back to me!
On Treasure Hunt, it feels like it would make more sense if the artifact count was total owned, not total sitting in inventory. In the game in question I've wiped out the Vasari and competing AI, but now need to run my titan (and other capital ships with artifacts on them) into the pirate base and hope they can kill it, as it turns out scuttled capital ships drop no wreckage and the artifacts are then lost forever.
Assuming the pirates manage to down the titan it should be possible to complete the scenario, but I can't imagine the devs intended the climax of the game to require suicide by pirate, then picking over the wreckage of your own fleet