Visually grouping blocks in frames

Maybe you want to make a nice block library, grouping blocks visually with a frame using virtual subsystems (with a shadow). This seems to be easy in the first place but the z order of the blocks may be a mess and you won't find anything to set the it.
Through some internal magic the z order of overlapping blocks depend on the name of the blocks. There is no systematic dependency though, so just play with the names until the z order is right.

Have fun!