Searching for the Rune Sphere (remake)

On this hero, the map is completely unplayable. There's no room to maneuver in the designated area. There are hordes everywhere. There's no way to swim. What should I do in this confined space? Waiting and building up an army isn't an option. Here's an example of a gold mine. I don't understand what it's for. By the time I can break through this stack, I won't need it anymore. If I hadn't taken Inspiration with Righteous Wrath for overall speed at the start, I wouldn't have taken the sawmill either, lol. At the end of the second week, out of desperation, I sailed with everything I had, and then this happened.