Warrior, Mage, Rogue. Auto-translated

Let's discuss our favorite commanders and, at the same time, our favorite heroes. For me, both are mages. At level 5, there are EXTREMELY powerful spells, a good summon, damage, and other joys of life, and a mage attacks in an area. You say it's a weak attack? Well, well. In my campaign, I had an archdevil adorned with artifacts like a Christmas tree; it dealt over 300 hit points per turn and moved at the very beginning. No one had time to react. Only those with immunity/resistance to fire survived to the second round, and even then, not always.
And, as a bonus, I play as a mage because I like the demon mage; he's handsome, has a beautiful voice, and attacks beautifully.

I've played through campaigns with mages, and I generally like warlocks (except for the demonic one, and Nosferatu isn't great, although his mass damage is decent when upgraded).
I like the human warlock the most.
If you're playing with friends, you can also take a warrior, as he's durable and easier to start with.

I usually played as a Warrior for the same reason – it’s easier to start with. Mages are more suitable for campaigns and for those who enjoy long games. After all, fifth-level spells are very expensive, plus you still have to learn them, and while you’re mastering them, waiting for the required number of spell points, and then casting them twice… it’s quite a process, although it’s still an option.
But when playing with friends, it becomes very interesting to play as a Rogue. The only downside is that it’s harder to start, especially if you’re used to quick health regeneration. But there are more advantages – especially the expanded list of actions available to Rogues. If you do everything right, you don’t even need to factor in the cost of hiring Rogues. This includes robbing various shops and stores, scouting treasure vaults, and ultimately, being a complete nuisance – harassing the enemy army, stealing artifacts from the main enemy, dueling, or the most unpleasant thing – disrupting the army before a battle, when archers and mages suddenly end up in the front row, and warriors can’t immediately reach them from the back row. But, of course, there’s one big BUT – you need to be lucky, otherwise, your Rogues will be captured, and your money will be wasted

A mage is more suitable for campaigns and for those who enjoy long games.

That's even more of an ideal option for me. I won't calm down until I clear the entire map. And it's easier to throw fireballs at enemies than to chase them down with other heroes.
By the way, my main hero in the second game is ALWAYS a mage. And for variety, I take archers and melee fighters as secondary heroes. I usually ignore thieves altogether. I don't even always build a guild. Raw power is my thing.

Almost always, I choose a Warrior and a Knight, but sometimes I want some variety, so I take a Guild Leader and an Archer. I only use a Mage as the main hero for the Necropolis faction.

I like the Guildmaster, mainly for the speed. I also like the Warrior, but it's a bit slow. I don't like the Mage because it's too overpowered – 2 castles per day, plus reduced learning costs, and it's still slow.

Almost always a warrior and a fighter, but sometimes I want some variety, so I take a guild leader and an archer; I only take a mage as the main character for the Necropolis faction.

Don't you like mages?

Warrior. Because his favorite faction is the Legion of the Damned, and they don't have any healing spells, so the leader's regeneration helps. The only good mage is again from the Legion. His main advantage over others is flight. The Elven Dryad can fly, but often misses.

each race has its own unique hero with distinct upgrade paths, so I choose a hero based on the race.

I would say that all three classes are equally viable. I choose based on my mood or depending on the map in the second Heroes game.

In the third Heroes game, I either choose a Mage or a Warrior. A Mage in 80% of cases, because in the third game, you can take any hero, and magic bonuses are great. It's very difficult to level up a Ruler through battles.