What skills should I upgrade for Friede in the final mission of The Grand Escape?

Hello everyone, I'm 14 and have been playing Heroes since I was a kid. I've learned to play well with only one faction: Haven. It's simple; they are always on the defensive, and you just need to let the enemy get close and then attack. As for skills: DEFENSE, ATTACK, LIGHT MAGIC, LUCK, BASIC LEADERSHIP, or vehicle control. When you level up these skills, they manifest in all the creatures in your army, and if your hero is level 30, creatures like Paladins can have an attack value of up to 50.