Defensive gameplay and other tactics.

Speaking of drawn-out battles. In the "Tribes of the East" expansion, in Arantir's campaign, there's a mission where the finale involves forming an alliance with the orcs. So, on the left, there's an orc city that seems impregnable at first glance, because it contains hundreds of cyclops and a few other creatures. But by using the tactic of using the "Necromancer's Mark" ability, you can take the city with an army that is 10 times smaller than the enemy's.
To do this, first, make the cyclops go berserk; they will kill all their allies. Then, using blindness, vulnerability, Necromancer's Mark, and Raise Dead (and all these spells are usually already known to Arantir by this time), you can level up units to level 3-4 without losing mana or units (assuming you are still far from the level cap). This method wasn't discovered by me personally, and this topic has already been raised in the "Walkthrough of the Tribes of the East" add-on thread, but I won't hesitate to repeat it, because this maneuver, in my opinion, deserves public attention.

If you're talking about the Zogsox city, the first time I made the cyclops go berserk, and the result was disastrous. The cyclops first wiped out their own army, and then mine. I passed it like this: first, the warlords move and stop right at the gates, followed by the cyclops. Then, place berserkers on the warlords; they attack the cyclops, who in turn kill almost all of them. Next, cast blindness on the warlords; they block the exit from the city because the cyclops are behind them. Then, use Dominate on the centaurs and berserk on the rest, except for the cyclops, and try to place them so that they attack the cyclops, because the cyclops are the most dangerous thing there. After the orcish troops destroy each other, about 200 cyclops remain. Luck played a big role here; I was very lucky, although I had luck skill upgraded, but still, this rarely happens: the cyclops missed twice against the ghosts, and they retaliated successfully.
By the way, in this battle, Dominate cannot be cast on the cyclops; if it could, it would be much easier. And I also think that you can only pass this battle because it is not mandatory.
In general, this is a very striking example of the power of dark magic; you cannot take this city with any other magic.