Why not simply use the Education skill for military history and tactics? It does deal with what previous generals did in a historical perspective.

Use the appropriate skill for more hands on activities such as Stealth, Combat, and Inspiration. Perhaps give a Boost die when appropriate based upon a tactical analysis of the situation.

This would depend on what they are exactly trying to do really. Depending on circumstance I would probably go with Int/Leadership, or possibly education maybe just a raw Int check, modified by the characters background/career/specs.

In otherwords, I'd make it up on the fly.

Why not simply use the Education skill for military history and tactics? It does deal with what previous generals did in a historical perspective.

There are plenty of soldiers that never went to West Point, or read many books on historical battles, that spent a lot of time on the ground performing real world applications of defenses and offensive operations. I trust them more than a West Point grad with no real world experience.

That being said, I feel that Leadership coming out of the Career Specialization Mercenary Soldier best reflects the idea of setting up defensive or offensive operations without the need of adding a custom skill. While Leadership with the right Talents out of the Mercenary Soldier tree effects Discipline checks of others, it seems easier to also add a boost die to the dice pool of players on offensive operations and a setback die to the dice pool of the enemy on defensive missions.

The boost die could represent the calm and confidence that the "Leader" brought to the party before the mission. Where as the setback die could reflect the placement of interlocking fire that causes hardship for those attacking, or well placed cover. While cover can not stack, it would free up a maneuver giving the advantage to a defending force.

This is just the ramblings of a player trying to make it simple without the need of introducing another XP sink in a custom skill.