Respect to Perapolken and everyone who came close to victory.
I had never played online or offline tournaments before. But during this walkthrough, I learned a lot of new things.
As for the walkthrough itself, there were only 2 attempts.
1. I gathered friendly monsters, went outside, broke through the elves, sailed to the dungeon, restored mana in the whirlpool, then went to kill the slow meat. The army was very modest because I didn't take diplomacy, so only ~55000. There was no question of any quests there ;)
2. I started the same way, but I didn't touch the elves—only picked up the eyes. Instead, I took earth magic and diplomacy in the witch huts, gathered a few more neutrals, and went through underground teleports to kill the four-legged 6th-level creatures. In the end, I got ~70000=level 19.
Realistically, I could have gathered another 10-20 thousand on those same creatures if I hadn't been so wasteful with mana. But the multiple saves just got to me, and by week 4 I was saving rarely—I no longer had the strength to replay.
I hope this small experience and studying the winners' saves (they will be uploaded, right?) will help me and other newcomers in future tournaments...