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

Impressive, especially at that level. But the chance of getting a Crystal is still only 1/3, but if you get it, it's a sin not to use it. Things are much worse with mines, especially with a Black Dragon.

I agree.
But I also cleared Utopia with mines. The level, however, wasn't 10th, but 17th. The map is a modified one for testing the speed of Warlock leveling (on the Nival forum) called "Ring Road." Instead of a city, they put Utopia. The summon was only Advanced, and it was either the 8th or 9th day. Before that, I simply got 15k experience from the Sphinx (he is also in the original map), which is why the level is so high. :)
There, I had to sacrifice a couple of Griffins to keep the Black Dragon in its position.:(
And on the mines, the Emerald Dragons went wild.