I think the "clone" issue might be bay's version of the classic hasbro strategy.....REPAINTS
A nod to the generic background Seekers in the G1 cartoon or Hasbro's policy of repaints are the two most obvious explanations.
I'd actually like to see an all new villain or villains to be created for the 3rd movie as whilst the nods to G1 can work effectively it is getting a bit boring seeing the same old characters rehashed or referenced in each new incarnation of Transformers.