Let's consider the buildings in the background of this scene. If you assume that your job is to keep them separated so that the viewer can tell how many there are, then it makes sense to identify how they are different from each other and make sure those differences are apparent. Three buildings, three shapes. But is that actually necessary? You could look, instead, for how they are the same, and treat them as a single dark shape. Depending on the job that those buildings are meant to do in the painting, it may be advantageous to have fewer shapes, overall. It almost always is.
When I squint at the scene the buildings merge into one shape. As such, they effectively form a background for the lighter cars and still display their idiosyncratic profiles. If you painted them as a continuous dark grey form you could add further information by increments and stop well before overdoing the description. Err on the side of too little information. You can always add more.
How many bales of hay are there in this scene? How many shapes does the haystack comprise? These are two different questions which can have two quite different answers.
Whose job is it to count the bales? The artist's? The viewer's? Nobody's?
You can look for whatever it is that separates the individual balls from each other, or you can start by looking at what they all have in common. Make the most general statement first, then the next most general, and so on, until the story has been told to your satisfaction.
Try painting the overall shape of the stack the color and value of the sunlit areas. Is that enough? If not, the next most general statement would be the shadow shape, which could be painted right over the local color. Is that enough? If not, what next?
How many shapes are there in this scene?
Using these photos or the ones you brought from class, please experiment with grouping adjacent shapes to simplify the composition. Ask yourself how you know when you have separated them sufficiently.
Also, please bring a pile of cheap paper for the quick poses at the beginning of the model session next week.