Secondary skills in Heroes 3.

I categorize skills into four groups: essential, semi-essential, skills needed only once throughout the entire history of Heroes games, and intermediate skills (depending on the game's conditions). The first group includes: diplomacy, wisdom, logistics, scouting, one type of magic, ballistics, war machine, and others. The second group includes: attack, defense, and others. The third group includes: eagle eye, divination, intelligence, and others. And the fourth group includes: navigation, scholar, and so on. By the way, skills are not balanced against each other at all (except for attack and defense). Is this a good thing or a bad thing?