The way I see it Herman, is that it's like other tools. Take for example a spanner. You could have a flat spanner, a cranked spanner, ring spanner, open spanner and so on, all the same size. Two or three different types of spanner may do the same job. Some jobs though require just one type and none of the others will do the job. A job that requires a box spanner come to mind. Among both my late father and father in laws tools we found spanners that had been adapted to do specific jobs that they couldn't find spanners for in traditional tool shops of the day.
All these swivels are variations of the same tool, and some are better suited to one persons needs than others. Some of us have taken what's available and adapted them to suit our own needs or preferences. It looks to me that you have done the same