The scenarios have fog of war, limited briefings, etc. That means the first time you play it you will not know nearly as much as the second and subsequent times.
Once you throw in artillery, knowing the enemy set-up, strengths, etc a scenario plays very differently after the first time. So do you design scenarios focused on the first time experience? Or do you worry more about replay value?
And if you download scenarios are you looking for a single fog of war experience or for a scenario you can replay to master?