The most powerful hero of the Dungeon faction.

Everything is exactly as you say! Minotaurs hardly participate in battles! But the catch is that all initiative-based troops will be destroyed in any case; what normal player would let, for example, Furies or Lizards live? Furies deal a lot of damage, but their numbers and hit points... Why would you want to control Minotaurs? By the time you control them, and they move with their meager initiative, the battle will already be taking place on the enemy's territory, and the Minotaurs won't even reach their own side; it's better to control a Fury or a Lizard. Put the Minotaurs in a corner and forget about them.
In the late game, the Warlock has few chances, whether it's Sinistar, or Iranna with Furies, or Kifrah. Kifrah just lasts twice as long as the others. The poor Minotaurs will be overwhelmed by a crowd of enemies, but nevertheless, the Warlock himself will deal more damage than other Warlocks.
Still, I don't see the point in a Warlock developing anything other than Chaos, even in the late game (except for Orcs); then there's no point in elements or spell enhancements, and what makes the Warlock better than another mage hero? With good witchcraft, elements, a lucky Wizard, and if you're lucky with the Creature Ability, the Warlock can deal 10,000 or more damage, freeze the enemy, and halving their defense is also important.

Again, you need to consider the opponent. Against Stronghold, you can put any hero in the late game, but there's still no chance of winning. Against Orcs, only Leto is an option, no other choice. Against Inferno, Iranna works - Furies at the beginning of the battle destroy either Cerberuses or War Horses, depending on which they reach. And then the main troops beat up the soft-skinned Demons. There's almost no chance against Dwarves. Against Wizards, you might as well take Shadiyah to minimize the damage from constant shots, but even then, victory is unlikely. Against Humans and Necropolis, it's really worth focusing on Chaos, upgrading the Creature Ability, wearing a Rune Set, and other enhancements. Erin, with her extra shot, would be a good hero for this. There might be a chance.

Against Orcs, I tried playing in the late game just for fun. I created near-ideal conditions for the Warlock - no Silence on the Orc, all the necessary artifacts on the Warlock. Instead of Assassins, I put Blue Druids from another castle in the battle, which increased the Warlock's magic by 30.

First, I tried to upgrade the hero's magic of light. I wanted to focus on Divine Retribution. I put on the Phoenix Cloak and upgraded Lucky Charm for a greater effect. I attacked creatures with water affinity. The result disappointed me.

Chaos was only slightly better.

But races without resistance take 30-40k damage.