What is the "finished" and "unfinished" size of each unit supposed to be?
After looking at the picture more carefully - it looks to me like the left side of the chevron unit was cut narrower than the right side.
I measured the unit "on-screen" - and even allowing for seam allowances, I am thinking that the left side is cut about 1/4 inch narrower than the right side of it.
How are you making the chevron units?