You cant script war, and thats not the idea anyway. The point is, to make such a video, we need as many viewpoints as possible.
The easiest way would be a demo record feature build in the game. That would make recording piss easy for a whole lot of people, as its just putting a command in, and then play. After that, send it to whoever, and your part is done. That would also ensure that the final recording can be done in super high quality.
Hmm, gotta ask if a record feature is planned. HHIIIGGBYYYYY?
Korn, a cameraman would only be useful for a overview of the battle. Usually, most of the footage should be first person, with UI. You dont want to show a scripted version of combat, you want to show the life action happening, the decisions from individual players, and how they all affect each other. You dont want to see a air raid coming and bombing down stuff, you want to see the whole process of this air raid forming, going out, and bombing stuff.