Secondary skills in Heroes 3.

This is what I'm going to level up for my hero:
1. Ballistics*
2. Artillery*
3. Wisdom*
4. Logistics
5. Diplomacy
6. Leadership
7. Attack
8. Defense
The skills marked with * are, in my opinion, the most important.

If you level up like this, the question is, why Wisdom? Sure, you'll learn all the magic, but without leveling up the schools, there's not much point... It's better to replace Ballistics and Leadership with Earth and Air magic, because in a simple three-hero setup, artillery is only good for defending castles...