The Lord is more alive than dead

I've been playing Heroes for about 7-8 years. I don't consider myself a pro; I'm far from it. I just enjoy the game. This map completely wrecked me... I tried to beat it 3 times, with zero progress. I don't understand how to quickly capture the Elven castles without getting my butt kicked by the orange and green factions. The first time, I reached the point where the green faction appeared, but I couldn't find a way to the castles. The second time, both the orange and green factions appeared, and after a couple of weeks, they killed my Nightshade. I didn't complete the task of capturing the Elven castles, the green faction received reinforcements, and that was it. The third time, I quickly captured 2 castles, found the orange fort, killed everyone, boarded ships, and reached the orange castle, but I didn't understand how to approach it... I went to the nearby building – the pyramid. I was killed there in 3 seconds))) Either I don't know how to play Necropolis, or I'm just terrible at this game. It's even more frustrating when people write here, "Yeah, I beat the map easily." Oh well, I'll come back to it and write that I finally beat it.