More on dioramas--
I think a diorama should tell a visual story. When I look at one that's been done well, I don't have to, or shouldn't have to look at the title to understand what the diorama represents. When I first saw yours, my first thought was, "Oh, that's Meade at Gettysburg." You've done a good job in that I wasn't surprised when I read what your diorama represented.
When you're thinking about building a diorama, you first and foremost have to consider scale.
Every man-made feature of the diorama, the buildings, fences, etc. have to match the size of the figures.
And, with larger scale figures means that there also has to be more details in the diorama; the figures will require more detail in their painting, the buildings will require more detail in their construction, and the landscape will require more detail. And all of this means you have to be subtle in what you do. So just keep in mind that when you use larger figures, you'll need more detail in everything.
You've done a good job so far. You could leave it the way it is and it would be fine. Or, you could add some small details that would take it to a higher level. Look at the original picture of the farm house and get some ideas from that to add to your work.
How about a vine growing on the side of the house? Shouldn't the floorboards of the porch look look like they've been used? A little dry brushing of some light brown paint on the steps and the area of the porch in front of the door would give it that "used" look. A little wash of a light brown on the house will give it a more realistic look, like we've already discussed above with your roof. You've got a walkway from the gate to under the table, but then it stops. Continue it up to the porch, and add a few tiny touches of darker colored paint to the gravel. It' shouldn't be a uniform color. Do you see a uniform color in nature? Brush some lighter color of green to the outside layer of leaves to the tree in the corner of the yard, it will give it some depth. Look at a tree in your yard, the leaves are all a very subtle colors of green, with the outmost layer of leaves being a lighter color where the light hits them. How many different colors of brown do you see in the bark? And the ground under the tree should be a darker color as it's in the shade. There is a pile of logs outside the fence. Notice how they are not a uniform color, but have subtle shades of brown and gray on them? This is the look you want to emulate. I can't tell from the picture if the map laying on the table has some lines on it. Take a pencil and add some lines to show the roads and put a small rock or whittle a bottle or coffee cup to hold the map down so it doesn't blow away. All this stuff will add some realism and detail to your work and take it to another level.
And I don't want to hear you complain that "I can't do this" or "I can't paint." You can. What you're really saying is, "I don't know how to do this" which is ok, because none of us knew how to do this when we started. You're just afraid to let your inner child out. Look on You Tube for ideas on how to use washes and dry brushing and how to those people make a diorama. I could write you pages of what I would do to complete your diorama, but you can learn how to do all of this within 10 minutes of a little You Tube viewing.
You are so close to completing your diorama; you're like 95% done already. Adding a little subtle texture to the colors of the roof, the home, and groundwork will really finish it off. Your inner child is screaming to be let out! Let that boy go!