Now we're getting somewhere. You're first impression implied to me that you just wanted to turn the GC scenerios in Battle scenerios. Which is easily done but you would run out of units in a few years. But now I see you want to add specific events to give more units, tech, orders, etc, etc. What you have described now with the invade poland mission and the french defense mission - they don't need the GC campaign. They can be just made like a normal battle scenerio.
However, I'm assuming that you want the whole world involved because they'll have an impact in certain missions? I'm not sure here, as what happens when you defend france on time, does the game continue with a new mission or end there? If it ends there you certainly do not need the whole map for that game.
If say you were playing france and defended it and then you were given a new mission then I can see why you would need the rest of the world as the war would just continue. But to keep giving mission for the entire war would be insane coding and event making. You could probably do it for one country with a couple months of work but several countries would take a full dedicated team.
I'm probably missing the point again