Amendment to section 5.2.1 of the Hv rules (regarding quick-cast spells).

Playing with 2 main heroes is indeed an art, because it involves dividing troops, experience, and artifacts, and often battles take place on a razor's edge, where even a slight lack of power can lead to significant losses and, consequently, a loss of momentum.

But even here, there are hidden challenges.
With Dungeon, you can play with a Shaker and a Dimmer simultaneously (if the latter has no restrictions), and I don't think it requires much skill; one focuses on trolls, and the other on everything else.
And with Necropolis, you can potentially send heroes to 3 different fronts (if you have good luck in the tavern).
Galtran
Tant
Aislin