A player winning the National Championship and a Heisman has happened 11 times since 1935. Paul Hornung won a Heisman with a two win season. Winning both is rare and not realistic.
Paul Hornung, QB, Notre Dame, 1956
Hornung got a free pass to the Heisman in ‘56 because he was a quarterback at Notre Dame — even if the Irish went 2-8 that season. He threw for 917 yards and had more than four times as many interceptions (13) as touchdowns (three). Syracuse's Jim Brown, who rushed for more yards (986) and touchdowns (13), finished fifth in that same voting class.
For anyone to pretend that every Heisman winner was the most deserving player is ludicrous.