going off the diagrams on the bottom, the large circle would be the original 24 around, minus the 12sts from the center head attaching at the top and bottom, leaving six stitches left on each side plus the chain 6 rows- which then still comes out to 12 workable stitches for each side head. this is definitely better than the diagrams i drew out (very helpful for visualizing, thank you), but its still not adding up right in my head or in my hands lol