While your joke is funny, it is not accurate.
Any plan in the game is an offensive plan, so planning is an attacking order. And the objective is to scout out the landscape around the frontline.
However, what I would like to see, is a revised planning system. Instead of having a planning bonus against a frontline, why not have a planning bonus against countries? After all, that seems WAY more in line of what many pre-war plans looked like: "How can I defeat country X?" So, you give your general staff the order to plan against country X, and they would go look for maps, for what tactics and equipment X uses and so on. This could be speed up by having high intel, too.
My joke was both funny and accurate.
Real life plans did not follow along the pattern you suggest. 'We're going to attack France'. Just not viable.
For example, the British Fourteenth Army decided what they needed to do to follow orders from above which could be something like capture Meiktila before the monsoon. In order to achieve this, they then decided what other objectives needed to be achieved before this could be possible. What hills would need to be in their control, what roads and rail lines would need to be captured, and when, and by which formation. How many planes would be needed to achieve air superiority. If that was not possible, what means could counter that, such as only moving at night and so on. Then, it needed to be decided what size forces would be needed to achieve all these aims, what supply they would need, where they would get it from and how. Roads, air, river supply, rail, and so on.
Then they assigned generals to play the role of the Japanese in a series of war games based on known Japanese strength in the area at the time. It was taken very seriously and the 'Japanese' generals went all out to try and win these. Depending on what happened, changes were made to the plans to try and counter the strategies that the wargame generals came up with and to try and put contingency plans in place.
One such real life plan relied on a period of air supply, however getting silk parachutes (to drop the supplies) to the 14th Army was nigh on impossible at that period, but they came up with making parachutes out of jute. Would be death to a human paratrooper but it was only to drop supplies so jute was fine.
That is how plans are made in real life. Not just 'let's plan'.