The steeper the outside pitch and the shallower the inside the stronger a scissor truss gets. It looks like a 10/12 pitch in the photo above.
I would set the side roofs on the main roof to gain more pitch, it'll hold water and fail sooner at the pitch break at those pitches. Just let the scissor designer know what you are doing. I would try a sketch at 6/12 outside main roof, 2/12 interior,3/12 sidesheds and see how high they crawl up on the main roof visually.