Managing 8 heroes on the map.

On many maps, 8 heroes are not enough; the amount of work is such that even 15-20 would be useful.

That's absolutely true! It's strange that they still haven't implemented the ability to deploy more than 8 heroes on a map in Warlords (at least 10-12). They could even make each subsequent hero more expensive, so it wouldn't be completely free... For example, the 9th hero could cost 3000-3500, the 10th - 3500-4500, the 11th - 4000-5500, and the 12th - 4500-6500 (approximately). And dungeons should also be paid for accordingly.