I don't understand about the naked 'Cons, but the idea I proposed is pretty easy. They could also reuse the titanmaster gimmick and do it that way for both pretenders and powermasters.Sure, they could do that. They could do lots of things, but probably won't at this point.
I'm thinking of whatever would be quick, cheap, easy, and not leave a bunch of naked Decepticons wandering around peoples' homes in the dead of night.
For example, Bludgeon could be a core "master" block bot (in his core robot colours) and have a small green tank/weapon that he can combine with and a Pretender shell that turns into a vehicle and Samurai Skeleton. The mini green tank could attach to one of his arms via 5mm ports (further homaging the original toy) and the inner blockbot could go inside a cavity (such as inside an opening chest). Voila, pretender. We could also use our existing mini Bludgeon Pretender as extra armour/play value of we wanted. Heck, they could even use done if that rubbery plastic they use for swords for various parts of the shells to simulate "skin", etc.