The SWC is a "Viewfinder" camera, with guess focus. You view through the top-shoe mounted viewfinder. I sure wish I still had one. It is a "brother" to rangefinder cameras. If you take the VC 12mm, 15mm, or 25mm lens and put it on your Voigtlander, or Leica then you have the same concept, because these lenses are not rangefinder coupled. The Zeiss lens on the SWC is one of the absolutely sharpest super-wide angle lenses for medium-format film.
The SWC is a worthy companion to those that work with RFDR cameras. It should be welcome here. Also, not all Leica thread mount cameras have a rangefinder, you know. I believe the Russian "MIR" camera just has a viewfinder. The original Barnack Leica was just a viewfinder camera. You could purchase a shoe-mounted auxiliary rangefinder to use though, as you could do for this SWC.