Tactics for the Swamp (Fortress).

The Castle is simply terrible!!! No magic, no decent warriors!!! And it requires a lot of wood, which greatly complicates the development process, especially on expert difficulty!

I disagree. There isn't much magic, but there are excellent units (hydras, gorgons with deadly gaze, wyverns, and even snakes are sometimes essential), and the fortress has excellent defense! On expert difficulty, just build wyverns, and you can clear the territory and gather resources.