I bought this book for the Mary Gentle story. Unfortunately, I'd already read it, in her short story collection, "Cartomancy." That's an excellent collection; go read it! I was pretty disappointed that it wasn't a new-to-me story, though. "The Logistics of Carthage" is in the same setting as her 'Ash' books, which are actually the only books by her I haven't yet read. I own them, though, and plan on reading them soon!
I really didn't much care for the other 3 stories in this book.
The first is Harry Turtledove: "The Daimon." I've read one other book by Turtledove, and didn't like it. But, it was YA, and this isn't, so I had an open mind. But, I found it too concerned with military details, and didn't get caught up by the characters or plot. The premise is that Socrates joined a Greek military expedition to Athens.
The second is "Shikari in Galveston" by S.M. Stirling. This is a prequel to his "Peshawar Lancers" book. I've previously read two other books by Stirling, and really quite disliked them. It's not that he's a bad writer, I think I just have a very different perspective on the world than he does, and something about his worldview and attitudes toward just about everything, just how he sees people - it annoys me. But if you are a fan of the writer, you will probably like this.
The book concludes with a Walter Jon Williams story. I've read 3 of WJW's books, but I think, all back in the 80's, so I'm not really up-to-date with his work. What I've read was all sci-fi/cyberpunk; while this is a Western. I've liked, but not loved, his work - and I feel similarly here. The premise of "The Last Ride of German Freddie" is that Friedrich Nietzsche ends up in the American West hanging out with Doc Holliday and the Earps. Amusing, but not amazing.