Good question. Does the Bible give us any more hints?
Father, Son, & Holy Spirit are One, are they not? That's 3. Jesus prayed, in John 17:21 that they ALL may be one. That would have been at least 12, right? So, the idea of more than two being involved in a one-ness isn't totally illogical or impossible scripturally.
On a more practical note, some years ago I noticed raindrops on a window pane. One drop began to slowly move. It soon encountered another single drop and they merged, becoming a larger single drop. The two had become one. Shortly the new unified drop encountered another single drop and merged. Then another and another.
In each case, a unified, inseparable WHOLE merged with another WHOLE, and the two became one.
To me, that is a beautiful picture of marriage between ANY man and woman, whether the woman is the first to merge with him or not. The end result is a new whole, inseparable, a family! Can anything be more beautiful?
One final lesson from the window: As the raindrop grew, it moved faster and faster. Not just the original one or two raindrops, but the whole united "family" of them. United, they got much further than any of them would have gotten alone!