Officers and Skill Books
For the sake of keeping this simple only the purple officers will be discussed. Don't Upgrade the Unworldly skills on Directors - focus only on Breakthrough skill. You're a fighter not a farmer!
Officers
Skill Books
Warfare
Until you get to c33/c34 you need to focus on 3 skills for your warfare officers: * Long Range Attack * Long Range Expert * Melee HP
The rest of the skills can be broken down and used to pump those up. Once you hit c33/c34 and thinking of switching to midrange then swap in the appropriate midrange skills.
Strategy
These officers can use different books depending on which ones you use the most. Loreline can be used with draft skill and Barney with draft skill to help troop recruitment. Saki and Morga