Skilled Counterattack - Experienced Tactician Skilled Offense - Archery - Battle Fury - Retribution Skilled Defense Skilled Leadership Skilled Light Magic - Protection - Holy Vengeance Developed Logistics
Regarding creatures. I think it's not advantageous to use them for humans - Retribution is better. Unless the opponent is a Necromancer, that might be an exception. Humans' ballista isn't very strong. After all, its damage calculation takes into account knowledge and attack, and humans develop their knowledge slowly. The ballista is only good for Orcs and the Demoness Deleb.