3rd gen Charger was a coupe counterpart of 6th gen Coronet. Making sedan and wagon of this, it'd be like making another car, i think it'd take another year. And they are similar, but over the run, were stylistically straying apart from each other. Road Runner/Satellite Sebring would make more sense, because just the outer body panels are different from Charger.
Would make more sense to do 1971-1972 plymouth satellite and road runner, as they are extremely more similar than a coronet is to the charger .