Hi! Instead of making them Adaptive, you should set them to Flexible. Adaptive and Flexible are two different concepts, even though they feel the same in your workflow.
Adaptive is for geometry deformation (adaptive feature or adaptive sketch). In Inventor, all instances of a definition have to have the same geometry. Therefore, Adaptive is only allowed in one instance of a definition. As you have seen, the second subassembly cannot be made adaptive, because Sub1:1 and Sub1:2 belong to the same definition.
Flexible does not change geometry. So, it can be used in multiple instances. What it does is exposing the degree of freedom between the components in the subassembly, which is exactly the workflow you are attempting.
Thanks!
johnson.shiue@autodesk.com
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer