You don't need Lt. Heavyweight to KO Stevenson(as D. Boone demonstrated). Canelo is clearly the more skilled boxer but Stevenson has a puncher's chance.
D.Boone KO’d Stevenson at SMW and Boone dropped just about every top SMW and LHW he fought he had serious power. Again he said prime for prime in 2013 Stevenson could pull the trigger and was a powerful counter puncher.
I have little respect for Canelo in 2021, but Beta-2 Canelo would drop superpimp with a left hook - and early. Boone 1 all over again.
You're arguing that 2013 was Stevenson's prime(@35-36 years old) in which case it can easily be argued that 30yr old Canelo has not reached the apex of his prime.
I just believe that his Punching power that year would be too much at LHW for Canelo. If we were talking about SMW then I would favor Canelo more. Hypotheticals doesn’t matter with him anyway because he’ll find a way to duck if Canelo was at that weight. He was only facing unranked LHWs during his reign.