HI THERE. I TOOK THE LIBERTY OF MAKING A DIAGRAM. Warning: Large.
I guess the only issue becomes:
(1) was the 13th tribe inherently Cylon, insomuch as all the tribes were Cylons?
(2) did the 12 tribes while on Kobol create a race of Cylons, ergo the "13th tribe"?
SEE. FUCK YOU, EPISODE. I HATED YOU FOR ALL YOUR TALKING, BUT LOOK WHAT YOU DID. I MADE A DIAGRAM.
Ladies and gentlemen, I'm back.