Waoh, thanks for the prompt reactions and the lively discussion, just great!
As I encountered several, possibly unrelated problems (bugs??): Should I create several issues, one for each problem (bold in my first 2 posts)? Or should we discuss all the issues first here in order to discriminate real bugs from missing knowledge on my side (e.g. how to move regions between tracks in Ardour 6)?
The import-ordering issue seems to already be identified, so I’ll start with that one in the tracker. But what about native support for polyphonic wav-file-import? Should this be a separate issue? I could imagine that it would be rather simple, once the file-ordering is fixed: Just chain the splitting-step (of import to region list) with the import to single/selected tracks and iterate over this for every selected file (if as sequence is selected).