Canelo isn't going to diffuse Benavidez' attack with stationary feet and pure head movement; David will simply throw in feints, alter his attack upstairs and downstairs, and alter the speed/power in his punches. Literally everything he couldn't do against Plant because Caleb wouldn't stand still. If Canelo spends the fight trying to offset Benavidez' attack, he'll never get going on his own attack. He'll have to take some real damage in order to get the job done.I disagree.
The biggest advantage a tall fighter has is the ability to just pull his head back into a safe zone. But Bena never does that. He relies mostly on blocking shots with his gloves, plus some lateral movement. Canelo will have all the advantages that a shorter fighter always has, with the most relevant one being that it's harder to throw an uppercut against a much shorter fighter. One of Bena's main weapons is the uppercut.
Bena is also somewhat susceptible to body shots, as he's tall and likes to keep his gloves high. Canelo's great and throwing hooks to the body, and being so short, it will be even harder for Bena to see them coming.
And finally, while Bena's #1 advantage is his exceptional hand speed, Canelo has the best defensive head movement in the sport today. If anyone can avoid / diffuse Bena's standard attack, it's Canelo. That means Bena will have to rely more on slower power shots, and that means fighting closer, where Canelo rules the land.
Even in moving up in weight, Canelo has been able to play the stalker and walk his opponents down, controlling range and setting up his heavy looping counters. He would not have that luxury here, and it would be interesting to see Canelo trying to fight off of the back foot.