If we are going to shuffle modified old terms on to new toys based on vague similarities than old Cog (and old Six Gun) are far more similar to Siege Weaponiser not Duobots. As Ralph points out these have a specific spring loaded gimmick to merge the two.
A recoloured Overlord as a new Flywheels might well be a Flywheels but he wouldn't be a Duocon.
How do you reckon these work then? Where does the sentience go when in vehicle mode? Is the bit with the head inside intelligent and the other vehicle a drone under remote control? Both halves can't have a separate intelligence or they'd just argue. Or does the sentience take an omniscient role and operate both vehicles simultaneously?