The most challenging maps for you.

What is this perversion? :)))
He should definitely have: leadership (starting skill), water and wisdom (walking on water), scouting (to reach the island with cyclops, although you can use 2 heroes with walking on water), logistics (obviously), and then options. You can take pathfinding, or armor/offense. But taking 4 magic skills is definitely not a good idea. 2 elements are more than enough.

Scouting on the second hero, it's not difficult to synchronize them. What's the point of loading a skill slot with junk, just for that one moment with the cyclops? Fire is needed for the expert skill "Blind" against story dragons, and air is for the air magic book. Leadership, wisdom, and speed boost I considered self-evident. Regarding leadership with artifacts, I'm not sure if it's critical.