Ogo

Played through it again. My hero reached level 632. The final save is attached.
I got the bonus due to better skill development and obtained education immediately. However, I couldn't lure the blue hero to the mines, as I did the first time.

Interestingly, for this map, the hero's difficulty is easier than others because it provides hero skill development, but resources are practically not needed. The main hero leads all battles with specters, which are not available in the city.