re: #96 Decatur Deb

In the 60s, Poul Anderson did The High Crusade, in which the UFO baddies the land in medieval England are very good at interstellar war, not to good at swordplay.

[Link: www.amazon.com…]

There was another book whose name escapes me where the intergalactic rules of warfare had strict guidelines on what technology could be used when conquering primitive planets, so the aliens kidnapped a Roman legion to serve as their ground forces.