One of David Drake's earliest stories (and one of his best known), is "Ranks of Bronze", which leads off this volume of tales. "Ranks" dealt with a short, ugly campaign by a group of bought-and-paid-for Roman Legionnaires, the survivors of Crassus' utterly disastrous Parthian campaign. To the aliens, the primitive humans are useful puppets who can be used to conquer other primitive worlds. But THESE puppets have swords, which can cut strings... and their masters' throats.
The stories in this volume range from non-stories like S. M. Stirling's "Three Walls", which is a fairly dull run-of-the-action description of a battle, turned into a story only by a throwaway moment at the end which warns of what is to come in the final story.
There's also "A Clear Signal", which doesn't really feel as if it fully belongs in this book, since the political circumstances described don't match anything else, nor do the Romans even get mention. It's not a bad story, but it really belongs elsewhere.
Drake himself contributes "Lambs to the Slaughter", which I'd call the sprightliest tale in the book, being how one underofficer, known to all and sundry as "Froggie", manages to outwit both his masters and his enemies. I laughed like hell at the ending of this one, and Drake doesn't usually do that for me.
David Weber contributes "Sir George and the Dragon," which serves both as solid entertainment and as a reminder that humans are dangerous, whether they be Romans or English, and a tribute to what has probably been the finest weapon of battle ever created, the English Longbow.
Finally, Eric Flint's "Carthago Delenda Est" is the treasure of this volume, and it was worth getting this volume for this story alone, even without Weber and Drake's work. I don't want to spoil it, but read the other stories first, then read "Carthago." The beauty of this one is that you have to read the story to understand both why and how it ends, and in my case, it took me a few seconds to puzzle it out, but the reward for doing so was to know true joy.
Well worth the time invested.