"In honor of our fathers" - "One Khan, One Clan" [Campaign 3, Mission 2]

I haven't been playing Heroes for very long, but I figured out how to complete this mission on my own. Regarding those who wrote about the problems:
1. A turquoise player appears from the portal and starts attacking. The solution is simple – don't stay in one place. In the third week, I captured a second Castle, gathered resources, and built it up, and also captured an outpost, so I had an advantage. I caught up with him and killed him, and he didn't appear again.
2. The purple player sends two armies by sea. They calmly set up near the shipyard. I gathered armies, but before they appeared, my hero sailed around, collected various chests and artifacts, so I had enough to buy an army. So I dealt with two enemies, and then when I sailed to the green player, all that remained was to defeat Letos's army.
3. Then came the panic: how to get to the turquoise player? I sailed around for a long time, went through whirlpools, but it all led nowhere. I saw the solution later: on the green player's island, there is a shallow area behind the rocks in the water that blocks the path. I bought a talisman and went for it!
I hope my advice helps.