I always figured any non-13 Prime after that whole concept was put forwards would just be a normal Transformer who took the title as a symbol.  Like the many human monarchs who had some variation of 'god' in their titles for millennia, even the Japanese emperor till comparatively recently, being seen as either a decedent of or representative for their countries god.  So ones like Rodimus, Hot Shotiumus, etc make perfect sense.
Meanwhile at the very start if you think of the early Marvel comic, there should have been a single small naturally occurring gear sitting in a puddle (of oil, I assume, water being rather rare on Cybertron), as the first 'living' thing on the planet.
And that little gear was either Optimus Primordial or Primordial Prime, I don't know which.
			
			Meanwhile at the very start if you think of the early Marvel comic, there should have been a single small naturally occurring gear sitting in a puddle (of oil, I assume, water being rather rare on Cybertron), as the first 'living' thing on the planet.
And that little gear was either Optimus Primordial or Primordial Prime, I don't know which.