The Amazons DLC has now been released for Troy, and can be obtained free for two weeks if you have a Total War Access account.
If you'd like to know more about Horde mechanics, there's a video. Troy's Patch 1.2.0 has also been released.

As well as all this, Patch 1.6.1 for Total War: Three Kingdoms is now in beta.

Discuss Troy here and Three Kingdoms here!