Hi I have an thought.
by expanding yout process to include all these steps may help
Make 10 to 12 double group models
Use section tool to work into each outside group with group edit, copy paste one, section .to ea group model. Compometize inside group for later editing.
Use 5 different skp files to work ea scene way you want them.
Open another sketckup (6ea maybe ok) you cut and paste too and from.(child and parent)
Use layer tool in parent
Use scene tool in parent
Right click for context menu or double click all sections, to get action cuts. (your work out right)
Now play your scene.
pic_0016.jpg
The best way: is to double click on ea sections for action cuts. done.