[Note: This entry originally started out as an answer on Quora]
The answer may depend on what you mean by “a poly relationship with 6 people.” Dooes this mean “one person is dating six partners,” or “there are six people total in the polycule”?
In other words, are you talking about this (a poly relationship where one person is dating six other people):
or this (a polycule with a total of six people in it, but no one person has six partners):
Those are two very different things.
A polycule of size 6 is not at all uncommon. In fact, it’s a bit on the small side; I’ve been part of polycules with more than 40 people.
Large polycules tend to follow the same model we see on social media networks and business contact lists and pretty much anywhere else human beings form interconnected networks: a large number of people with a small number of connections (one or two partners), joined together by “metapeers”—small numbers of people with large numbers of connections.
I have almost no direct connection with the distant parts of my polycule. Not only am I not shagging them or dating them, other than the fact that we all belong to a WhatsApp group and a couple of Facebook groups and message groups, I don’t have a lot of day to day contact with them. So for example, the other partner of my crush’s girlfriend isn’t someone I see or talk to every day, though of course we know each other.
On the other hand, one person dating six partners? Six partners is a lot.
I can maybe see it if some of those partners are comets (loosly defined relationships in a highly elliptical orbit where you meet come together every so often, then end up apart for a while again) or long-distance relationships, and I would suspect it’d only succeed if most or all the people involved were some flavor of solopoly or RA.
But six close, life-entwined partners? Yeah, that’s a lot. It’s possible, certainly, but it’s a lot.