It seems as though you're a bit confused by how the product works, so I'm sorry if I'm stating things that are obvious....
These are polishes for application by machine. They have a carrier fluid for the abrasives (some kind of oil I think) that gets left on the car after you've polished a section. The oil that gets left behind isn't for adding to the looks of the car and it should be wiped off after you polish the section. In this sense, you wouldn't "layer" the products although you might use SIP first, wipe off the section, then use 106FF.
SIP cuts more than 106FF and finishes down slightly less glossy. If you would consider your car swirled you probably want SIP not just 106FF if working with PC (I have no experience with rotary and these products, you may be able to take out swirls with 106FF and rotary). Depending upon the color of your car, the hardness of the clear coat, and your standard of perfection you may need to follow up polishing with SIP with 106FF for the highest level of gloss. Many are able to get results with SIP and an orange pad that are "last step product ready".