The essence of the tactics when playing as the Dark Elves.

I just wanted to set the general direction, and you were supposed to analyze specific examples. If you wanted to show with this post that you play better than me, I wouldn't argue with that.

Not at all. I just think that you should have immediately moved on to specifics. And I don't consider myself a particularly strong player.
Although I'm not a big fan of the Tower, I think that Lethos is the strongest hero. He can easily take mines guarded by level 3 creatures in the first week, and with some luck, even level 4 creatures, which is largely due to the stupidity of the AI, which uses Wait after the hunters disappear and takes twice as much damage from Plague. Even with 3 spell power, during the invisibility, Plague will deal an average of 336 damage to the stack, and that's for 6 mana, and the hero himself can attack twice.
In terms of strength, Lethos can be compared to the Mechanists and can be safely banned along with them. In that case, in my opinion, it's worth taking Vaishan (Stalkers + a quick path to Lucky Charm + Mines) or Sinistar (Archers, and, as mentioned above, the ability to get Chaos Magic early). The problem with the Tower is that its first two levels require an upgrade, without which it's impossible to do without, which makes it somewhat difficult to develop on maps with a low starting city level. Previously, many believed that you should go for Hydras, and then magic will solve everything. With the appearance of Orcs and Counterspell for other races (and additional tactics from invisibility), things are no longer so obvious.

Now, about the example I gave earlier - the "Former Friends" map (Veteran, no time limit). It seems to me that it presents some problems for a Warlock-Mage, although there are enough resources there to build every day. This is because you can break through to the center with magical support and fight there, even if it's in the second week, but, as you know, equal players meet in the center. But if you run out of mana, and there's a real shortage of it, unless you find an artifact for Knowledge on your own territory, then things can get bad, because without an upgrade, the Tower is not very combat-ready at levels 3-5. 12 Druids are not 12 Lizards, and there may be 30 Vampires or more. Therefore, I think that the Tower should not try to grab a piece of the center, but, if possible, with full mana (there are wells before the bridges), attack the enemy and bombard them with Chaos. For such purposes, Kifrah with the Golem looks optimal, and she also transforms into a pretty good warrior. And if you manage to get Chaos with Deadly Cold on her early on, then you can even kill a Ballista (because machines can be upgraded not only by Mechanists).

Now I will express my opinion about the Creature Ability (CA). It can only be effectively used in a real game on a really long map and not with a starting hero. The starting hero will be responsible for development, and only then, with an army, you need to level up someone with CA. Otherwise, losses in tempo are inevitable. A good example: for Necropolis, the main candidate for leveling up CA is Deirdre, but as a starting hero, she is very unstable, because she often has problems with quickly getting the Mark skill. For me, CA is still an exotic thing, moreover, these skills differ greatly in strength, there is no talk of balance.