Walls and Ceilings - Size for wall frames/fake wainscotting

I am installing fake wainscoting using wall frames and chair rail. The frames will be on two adjoining walls. One of the walls is very long and there are a door and a window on that wall. The door and the window break the will into 3 pieces of various lengths (5'11", 13'2", and 4'5"). I found a great book on wall trim and it gives a formula to calculate the size for the wall frames. I was going to try to make all of the frames 35.75 X 23 inches with 3 inch spaces between. This will leave me with one 26 X 23 inch frame on the right end and one 9 X 23 inch frame on the left end of the wall. The adjoining wall will have three 37.33 X 23 inch frames. My question is... should I put the small frames on each end of the wall or is there a better way to handle these different wall sizes.

As you've discovered, and are pondering, symmetry is the important aesthetic value.
I would use some paper or poster board or cardboard mock-ups. Expendable and easily rearranged.

Thanks for the suggestion. I will definitely use cardboard or painter's tape to simulate the frames before I cut anything.