I think in order to debate something like this sensibly we'd need to come to some agreed on definition of the term. We've had some exposure to what most probably consider the "swinging community" over the years and can attest to the fact the the philosophies of the individuals there vary widely. I find it hard to put a box around the term at all.
Here's part of "why".
In some earlier post on a different topic I tossed out the question of "swinging" as a "gateway drug" so to speak. A beginning step along a longer and more complex path. Because I've seen a reasonably substantial number of people associated with that lifestyle that really - down deep - were looking for more meaningful connections. And they were open to them. But most seemed to have no exposure or knowledge of polyarmory at all ! The minute "poly" seems to find itself into word a majority of people automatically connect it to "polygamy" and all the bad associations most people have of that (valid or not).
So although it seems on the outside that "swinging" may be all about "sex" the reality is somewhat different. Now granted - sex is a HUGE issue for most people in one way or another and a topic in itself. Hell sex is a big issue for all living species ! The fact that it's been suppressed in humans for so many years has only increased the desires.
So in a nutshell - I guess I believe we need to be careful about drawing too rigid a line between the two terms and to take every opportunity we get to educate anyone - regardless of "label" - who is "reaching out" into some of the possibilities that exist that they may never have been aware of !