Here's what I've got:
1.) Luck - Magic Resistance (standard), Luck of the Draw, Soldier's Luck (100%!).
2.) Attack - Archery (focus on archers), Fire Arrows (an amazing skill, especially when developing machines!), and Frenzy (attack, attack, attack!!!).
3.) Logistics (you can't do without it, IMHO) - Develop up to Plunder. (A very good and useful skill!).
4.) Machines (I love them the most!) - Ballista, Rapid-Fire Ballista, you can also choose an Enchanted Ballista, or a Catapult. (I prefer the Enchanted Ballista).
5.) Leadership - Rally, Sylvan Leader, Inspiration/Haste Aura.
This is a tactic for Ossira.
Bow down and hear our cry,
Our earthly rulers falter,
Our people drift and die,
The walls of gold entomb us,
The swords of scorn divide,
Take not thy thunder from us,
Take away our pride.
G.K. Chesterton: English Hymnal