What is your opinion about Heroes IV?

I would really like a couple of specific examples of when the same race, on the same map, against the same opponent, can apply a variety of approximately equally effective different tactics for development and combat. If possible, use an example from the ongoing World Championship; there are maps and reports there, which would make it easier for me to understand, because I'm not exactly an online monster, especially in the fourth installment.

Sure. I'll take a map of my own creation; if you don't mind, it will be easier for me to generate examples, because there are many things in the World Championship that I am less familiar with than I would like. Spleen. Start with anyone. Let's say it's a Life faction. #1 Classic: tactician, fast Life mage for the chariot, Life runner (or Order), Order mage (preferably fast, but Life is more important), angels, crusaders, monks. Combat method: either use the chariot immediately or after a mass rush. Send troops forward (including monks), and with a wait, take down the enemy tactician. If there is no chariot, the battle may go in any way, for example: teleport the crusaders and take down the tactician with two hits or Steal All, and then a mass attack. #2: tactician and runner, two fast teleporters, Life mage, champions, crusaders. Throw meat behind and take down everything that moves with a wait. #3: tactician and runner, two demonologists or demonologist + Life mage, angels, angels. Summon devils or venom, two stacks of angels to prevent the enemy from escaping our heroes while the meat grows. These are three of the simplest and most understandable options from the start. And there can be a lot of exotic options. For example, 20-30 catapults, or a fast Chaos mage with a spellbook, casting a cloud in the first turn. That is, I have named only three of the simplest, and there are still a lot of derivatives, plus completely wild options with guildmasters, etc. There are countless possibilities.