A workable idea... Quite possible... Now let's try to figure out how to let the viewer know the the vehicle's "Sorta broke down", since it's the focal point of the story. In Shep Piane's dio, "The Elefant's Dilema", we see a location somewhere in Italy, evidenced by a sign post pointing the way to Anzio in one direction, Roma in the other. An Elefant has pulled off the the road with several figures directing the viewer's eye around the scene. First, there's a crewman that has stuck a stick into the fuel tank, pulled it out, and is pointing to the bottom end of the stick as the commander looks at him from his hatch. Moving to the left side of the dio, we see a horse-drawn wagon coming along with two German cooks on it, one driving the team, the other munching on a loaf of bread. In the foreground at the side of the road and the key to the piece, is a digruntled AFV crewman with an array of bone-dry Jerry cans...
So the question here first is, "How do I show that the vehicle's broke down, and what's broken?" Is it out of gas (above idea), flat tire(s), thrown track, (easy enough), a broken axle from hittin' a well hidden old foxhole, blown engine (A large puddle of oil on the ground under the engine), etc?
Next, Is it an ambulance track or a combat vehicle? After that, where is it taking place? Eastern Front, Western Front, N.Africa, Italy, Sicily, etc?
Then we come to, is it near the fighting or few miles back? Is there a danger of discovery by the enemy?
After you decide that stuff, we'll move on... You'll want the vehicle and figures about 70% complete from this point on, give you a better idea of size and toake sure you have ample room on the base by laying it all out in a mock-up on a piece of cardboard or even just paper.
(Planning dios is my favorite part of building them)