Towards the end of the last great war, the Shadows buried a bunch of their vessels. Some were on Mars and others were yet elsewhere.
My question is... in 1,000 years, wouldn't Shadow technology have improved to the point of making those ships obsolete?
A few possibilities occur to me. One is that maybe the Shadows had discovered all that they could discover and that the Shadow ships were as powerful as they could possibly be. Another possibility that occurs to me is that maybe the rules of the conflict imposed restrictions on the ships that could be used - restrictions that the Shadow ships had met a millennia ago.