is the "anchor partner" concept useful inside a swinger marriage or just polyam jargon for what we already had

so a friend of mine who recently moved into polyam keeps using the phrase "anchor partner" to describe her live-in nesting partner of 11 years. she insists its different from "primary" — anchor is descriptive (this person is the centre of gravity), primary is prescriptive (this person ranks first by rule). and she said i should think of dh as my anchor. f44 m47, 19 yrs married, LS for 7. and ngl, it actually kinda hit. "anchor" describes how it feels in a way that "primary" doesnt — like dh is the thing that lets me move out into all the other stuff and come back. not a hierarchy, more an architecture. when i play with someone else its still in the gravitational pull of the home thing we've built. but then im going... is this just monogamy-with-perms in a new t-shirt? am i romanticising "we're married and have other partners" by giving it a poly-coded label. and is the LS, which has always been about the couple unit being primary, secretly already operating on the anchor model and just didnt have the word for it. people who've adopted "anchor" language inside their LS marriage — has it changed how you actually relate to play partners, or did the word just sit on top of existing dynamics without changing them. is it useful jargon or pretentious jargon. and how do play partners react when you describe your spouse as your anchor — does it land softer than "primary".