When five actors aren’t performing to the directors standard, they must take a different approach in order to succeed in creating the best war film ever.
I immediately think of Tropic Thunder. 🙂
I guess I would try to be more specific about their different approach. Is it a more realistic approach, do they have to resort to inciting a real war? Is it a deadly approach, do they murder the director and take matters into their own hands? Is it an outrageous approach, do they napalm a small island? Is it a desperate approach, do they pool their savings and create a Hunger Games of hired assassins that becomes an instant ratings success?
So many options. ;p
Who is the lead character? (The director?)
What is standing in their way?
What are the stakes, or in other words what will the lead character lose if they fail to achieve their goal?
I only ask because conflict is very important to a story, and in your story, there is a conflict but it is easily solved when the actors try a different approach. Nothing seems to be standing in their way.