Artania

Here's my strategy before the final garrison and castle (for the Elves).
P.S. The author chose the Orcs as pushovers... maybe I'll try playing as them sometime... but it seems like a real pain! I'm waiting for someone who has completed the game as Orcs to share their strategy if possible.
I personally played it like this: Orcs - Gnomes (I weakened the garrisons and killed the main hero in the sea) - Humans - Gnomes.