Connie, big thanks for offering to make me some die-cuts. If at some time I find the need I'll be sure to be in touch. Thanks for being so thoughtful.
Twice I typed the following info for those who may want to know the differences between stencils. Unfortunately my computer immediately deleted my brief explanation. I have been using stencils for many years and have acquired 3 notebooks full of stencils. They are more reasonable than many of our tools.
Layering stencils
I saw your post and realized no one had responded yet. I think what is happening is that layering stencils are designed in the style of the designer's creative interests. For instance several of Tim Holtz stencils can be used to create a college type project. Or a few stencils can create interest for backgrounds. Tim has a youtube demonstration explaining the differences with color, paper, design and how he uses them. He recently added some floral stencils to his line of layering stencils.
Altenew stencils
The floral stencils are broken into smaller pieces of the large flower so different parts can be shaded or accented. The company provides a colored printed layout of where each small piece should be located. Self-paced classes are available to learn Altenew techniques.
Concord and Ninth
Concord and Ninth has layering stencils called turnabout that helps one develop detailed pattern designs. One divides the paper into 4 quadrants and then colors the pattern in each quadrant adding a segment after each turnabout.
Greetery
Greetery stencils provide a marking on the stencil so that segments can be correctly connected by matching dots.
Many other artists have created new ways of using stencils. It does take some time to discover how each stencil is designed to be used. Have fun learning what works for you!