A THREAD FOR NEWCOMERS!

But there are a few more aspects. I've noticed that pro players already have a lot of heroes at level 115-116, at least 4.

There's also a question: is it always necessary to play with one strong hero and only level him up, or does it make sense to level up others as well? What's the best approach?

And, of course, I constantly see pros being able to clear the "Guard Tower" on some maps as early as week 1 or 2, which I can't do.

The number of heroes directly depends on the size and "content" of your zone and the map as a whole. On maps like Jebus, even ten wouldn't be enough if you could hire that many. In the first week, it's very important to find the balance of the "necessary minimum," because spending 2500 on a hero who just wanders around doing nothing can be spent on troops and other things. Personally, I usually have 5 heroes by the end of the week on the Small Map, although I often hit the limit.

Regarding leveling up heroes... You need to understand that in the final battle, it will most likely be decided by one hero, and a couple of extra levels will never hurt. But this doesn't mean that you should fight all battles with him. Even in the first week, you don't always know who will be the main hero in the end – it depends on many factors. After all, no one can predict that a hero with level 10 and attack/defense/magic skills will encounter a dungeon. I think the optimal approach is to level up everyone as much as possible, giving more importance to the presumed main hero (for example, if you see an Orcish Outpost with a horde of dendroids, as well as 2 stacks of zombies, gnomes, and golems, it's a sin not to send your main hero there on the first day, if it's not too far away).

Clearing the Guard Tower also depends on a lot of factors (which is why I love Heroes 3):
1. Undoubtedly, the player's skill.
2. The presence of "special items" like the Golden Bow, Mass Slow, Resurrection, or Explosion, which will allow you to clear it with minimal losses.
3. The Guard Tower itself (because it could be a Fairy Dragon, for example, and you have 100 golems from Pandora, or 100-249 dendroids, and you have archers with a wagon).
4. Timing. I think there are situations where even with the loss of 3/4 of your army, it makes sense to clear the Guard Tower.

P.S. Regarding chains and leveling up multiple heroes. In War of the Chosen, there is experience for creatures, and the number of battles is important not so much for a specific hero, but for a specific army. That's why chains are much more important there. I am always surprised and happy to see how pros fight dozens of battles with one army in a single game day, and the next day it's back with the main hero, and he goes like a tank towards his goal.