Auto-translated
In the first week, you should first upgrade to Hunters. With Hunters, the usual tactic is: first turn, go invisible, then the hero hits with magic as much as possible, wait with the Hunters until the right moment, then, before they become visible, hit without retaliation. This is how you can easily defeat almost any guard on wood and ore. Later, they are useful for eliminating archers and sorceresses. If you see golems, zombies, stone elementals, and other low-initiative enemies within range, upgrade to Furies and have them run up, attack, retreat, retreat further, and repeat. Furies can defeat any number of slow enemies; it's just a matter of time. You can gain experience for free. In the second week, upgrade Hydras to those that regenerate. Have them stand in a corner and wait while the Furies run out from behind them and attack the enemy. Try to develop the hero towards increasing mana. Don't forget to build the special building that increases knowledge by 1 as soon as possible. Take the Education skill and the perk with the bald man, which also adds mana. Take Spell Lore and the perks that reduce the amount of mana spent. Take Dark Ritual; you may need to use it sometimes if there are few mana wells. Try to get the knowledge boosts, sometimes accepting losses, as knowledge is very important for the Wizard. Be sure to build the second level of magic and learn a powerful Chaos spell there, such as Ice Block or Lightning; accordingly, take the Air Lord or Water Lord in the Chaos branch.
The general plan is: the hero levels up as a Chaos mage, trying to increase the mana pool as much as possible (this is really the number one problem for Wizards; enhanced spells are expensive, and knowledge is rarely gained when leveling up). The Wizard's army is small and expensive, so protect each unit; they are very valuable, and try to avoid losses. After building the mandatory Capitol and Castle, decide if you need dragons on the map and if you have enough resources and time. If you do, postpone things like Minotaurs, Riders, and Witches and save up for the dragons and their upgrade. Then, invest in all the magic and decide if you need Dark/Light magic with this setup. Since the Wizard's main stats are spell power and attack, take Chaos, Spell Lore, Attack, and Education. If you're lucky and get Luck (or have a hero with innate Luck), try to upgrade Spell Lore Luck; it's a very useful skill for the Wizard. There is also the option to take Battle to the Last and then, with fourteen Hunters, the number of Lightning and Ice Block spells per battle will double, with 600 damage (and with Luck, 1200), which will defeat almost any enemy, and if it doesn't, you can retreat and come back a second time to finish them off (Dark Elves, when using the Hit&Run tactic, are simply overpowered). In short, Dark Elves, with a well-thought-out approach, are a very dangerous opponent and are loved by many players. Play with them, master them, and you will love them too.
P.S. And by the way, I'll add: they have a market of artifacts in the castle, which often helps a lot. If you find a Pendant of Cold there and a Guild perk of Ice Block or Ring, that's great! Or boots +1 to speed with tactics - and the Furies become as fast as archers. And there are also elemental chains; you'll figure it out later, but it's also a good thing.
P.P.S. I forgot: Witches have the spell Confusion, and the Wizard has Education, which includes Unraveling. And if the main problem for you becomes the enemy archers, then take Dark Magic and Mind Lord, teach your Witches Confusion, and the archers are no longer a problem; the Witches have a lot of good and useful Dark Magic.
In the final stages, the Dark Elf turns out to be not only a strong mage but also has a very powerful army, with his attack! Against neutrals, the Dark Elf plays purely with invisibility, then reaches the main enemy, using this invisibility to inflict a lot of damage and retreats to the castle, where he revives himself, revives all his accumulated army, and comes with a bunch of Minotaurs, Lizards, and Hydras. The Lizards rush in, ignoring defense, and their first attack is death to all living things; then they are successfully beaten and die, but they take one stack of the enemy with them. The Minotaurs also turn out to be very cool guys, and while the enemy is killing the Lizards and Furies, their double attack cuts them to shreds. And then it turns out that 150 Hunters also do a lot of damage + poison + they reached the heart of the enemy in invisibility and stabbed. And the Hydras carry the whole game. They are slow, no one pays attention to them until the very end, when there are already only corpses around, and when the enemy hero realizes that he has no troops or mana left, but there are 30 Hydras left, which he simply has no one and nothing to kill. The end