There is an inyan to have 12 challas on Shabbat, to remember the Lehem HaPanim. There are different ways of achieving the 12.
I think that the braid concept is to have 4 challot throughout Shabbat of 3 braids to make 12.
The GRA held that there are 2 loaves at each meal (6 total) that are each cut in half, making 12 halves.
The Arizal, as mentioned in the Ben Ish Hy, had 12 rolls that he arranged on the table.
“I bake challahs I make it like a breakaway which is so much faster and still looks pretty.”
Some will do a breakaway with 12 pieces.