-touch "$from1dir" "$from2dir" "$from3dir" \
- "$from2dir"/sub1 "$from3dir"/sub1 "$from3dir"/sub2 \
- "$chkdir" "$chkdir"/sub1 "$chkdir"/sub2
+$RSYNC -av --existing -f 'exclude,! */' "$from1dir/" "$from2dir/"
+$RSYNC -av --existing -f 'exclude,! */' "$from2dir/" "$from3dir/"
+$RSYNC -av --existing -f 'exclude,! */' "$from1dir/" "$chkdir/"
+$RSYNC -av --existing -f 'exclude,! */' "$from3dir/" "$chkdir/"