Hmm... Baron Munchausen's comment about the Sergetti reminded me of something in my Last game start. It *seemed* like the Sergetti didn't immediately surrender upon encountering their first glimpse of one of my ships. I *thought* my score was easily 20x theirs at the time. But whereas the Last 5 or so races all capitulated upon learning of my empire's existence, I actually had to send a ship to the Sergetti homeworld before they realized the error of their ways. If I'd had weapons on that ship, I just might have destroyed their planet rather than accepting their unconditional surrender.
(Okay, so I had one tiny little CSM I on the ship. But if I'd attacked, their planetary defences would have laughed at my escort)
Any ideas why the Sergetti would require a greater than 10x score?